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Java codes

  1. 1. Table of Contents Chapter # 1 (The Genesis of Java) Q# 1. Write a java program which show hallow word app! Chapter # 2 (An Overview Of Java) 4 4 4 Q# 2. Write a java program to display a simple string. Q# 3. Write a simple java program to display a string and perform a simple multiplication. 5 Q# 4. Write a program which demonstrate the if statement.: 5 Q# 5. write a program to demonstrate the for loop. 6 Q# 6. Write a program which contains block of code in ―for‖ loop definition. 7 Chapter # 3: (Data type, Variable and Arays) 4 8 Q# 7. Write a program to compute distance light travel in 1000 days using long variables. 8 Q# 8. Write a program that calculates the area of a circle, use data type of double. 9 Q# 9. Write a program which demonstrate the char data type. 9 Q# 10. Write a program in which char variables behave like integers. 10 Q# 11. Write a program which demonstrate dynamic initialization. 11 Q# 12. Write a program that demonstrates the Boolean type values. 11 Q# 13. Write a program which show the effect of nested scopes. 12 Q# 14. Write a program to demonstrates the lifetime of a variable. 13 Q# 15. Write a program that convert one data type in to another data type 14 Q# 16. Write a program that multiply and add different data type variable. 15 Chapter # 4 (Operator) 15 Q# 17. Write a program which demonstrate the arithmetic operator 15 Q# 18. Write a programme that demonstrate modulus operator 16 Q# 19. Write a program in which various assignment operator is used. 17 Q# 20. Write a program which shows the function of increment(++). 18 Q# 21. Write a programme left shifting the byte value. 18 Q# 22. Write a programme that demonstrate the Boolean logical operator 19 Q# 23. Write a program which demonstrates the ? operator. 20 Chapter # 5 (Control Statement) 20 Q# 24. Write a programme that demonstrate if-else statement 20 Q# 25. Write a programme that show simple example of switch 21 Q# 26. Write a programme that show in switch break statements are optional 22
  2. 2. JAVA & OOPS Manual Q# 27. Write a programme that show the season when any month is given to it. 23 Q# 28. Write a programme that demonstrate the while loop 24 Q# 29. Using while loop write a program which display midpoint of two numbers. 25 Q# 30. Write a programme that demonstrate dowhile 26 Q# 31. Write a program using do-while to process a menu selection. 26 Q# 32. Write a programme that demonstrate loop control veriable inside the for 29 Q# 33. loop. Write a program in which for loop is used and find the prime number by using this 29 Q# 34. Write program in which two variable used to control the iteration of for loop 30 Q# 35. Write program in which two variable used to control the iteration of for loop using for comma 31 Q# 36. for loop. Write a for loop program in which initialization and iteration is moved out of the 31 Q# 37. Write a program of nested for loop. 31 Q# 38. Write a program in using break to exit a loop. 32 Q# 39. Write a program in which using a break to exit a while loop. 33 Q# 40. Write a program in which using a break to exit a while loop. 34 Q# 41. Write a program in which break is used like go to statement. 34 Q# 42. Write a program that used for a labelled break statement to exit from nested loop. 35 Q# 43. Write a program that uses continue to cause two number. 36 Q# 44. Write a program that uses continue to print a triangular multiplication of table for 0 through 9. 36 Q# 45. Write a program that demonstrates return. Chapter # 6 (Introducing classes) 37 38 Q# 46. Write a program that call this file BoxDemo.java. 38 Q# 47. Write a program that declares two Box object. 38 Q# 48. Write a program that includes a method inside the box class. 39 Q# 49. Write a program that volume () returns the volumeof a box 40 Q# 50. Write a program that use as parameterized method 41 Q# 51. Write a program that use a constructor to initialize the dimension f a box. 42 Q# 52. Write a program that uses a parameterized constructor to initialize the dimension. 43 Q# 53. Write a program that defines an integer stack that can hold 10 values. Chapter # 7 (A Closer Look at Methods and Classes) Q# 54. 1|Page Write a program that demonstrates method overloading. 44 46 46
  3. 3. JAVA & OOPS Manual Q# 55. Write a program that use overloaded method and convert a parameter into corresponding data type when compatible type of constructor is not available. 47 Q# 56. Write a program that shows the dimension of a box in various way. 48 Q# 57. Write a program that 49 Q# 58. Write a program that shows the overloading of constructors. 50 Q# 59. Write a program that is passed by value. 52 Q# 60. Write a program that is call by reference. 53 Q# 61. Write a program that returning an object. 53 Q# 62. Write a program that that use the concept of recursion and find the factorial of the numbers. 54 Q# 63. Write a program that shows recursion. 55 Q# 64. Write a program that shows the working of access specifies. Like we can access public methods and variables but not private one. 56 Q# 65. Write a program that uses variable , method and blocks Q# 66. Write a program that inside main() the static method accessed outside of the class. 58 Q# 67. Write a program that demonstrates an inner class with in for loop. 59 Q# 68. Write a program that demonstrates Strings. 59 Q# 69. Write a program that demonstrates some string method. 60 Q# 70. Write a program that display all command line arguments 61 Q# 71. Write a program that uses inheritance to extend Box 61 Q# 72. Write a program that show Super keyword implementation of BoxWeight. 63 Q# 73. Write a program in which BoxWeight extends to includinf shipping cost. 66 Q# 74. Write a program that demonstrate when constructor are called. 69 Q# 75. Write a program that show method overriding. 70 Q# 76. Write a program that use Dynamic method dispatch. 71 Q# 77. Write a program that use run time poly-morphisam. 72 Q# 78. Write a program that use abstract method and classe. 73 Chapter # 10(Exception Handling) 57 75 Q# 79. Write a program using exceptions in it 75 Q# 80. Write a program showing multiple catch Clauses. 75 Q# 81. Write a program that Handle an exception and move on. 76 Q# 82. write a program of try statements 77 Q# 83. Write a program that can be implicitly nested via calls to methods. */ 78 Chapter#13 (String Handling) 2|Page 79
  4. 4. JAVA & OOPS Manual Q# 84. Write a program that use override toString () for Box. 79 Q# 85. Write a program that demonstrate equals () and equalsIgnoreCase(). 80 Q# 86. Write a program that use == method to give answer. 81 Q# 87. Write a program that use compareTo() to determine sort ordering for a bubble sort. 81 Q# 88. string. Write a program that show how to use various index method t search inside of 82 Q# 89. Write a program that use substring() method to replace all instance of one substring with another within string. 83 Q# 90. Write a program that use trim() to process commands. 84 Q# 91. Write a program that convert uppercase latter to lowercase and lowercase to uppercase latters. 85 Q# 92. Write a program that define StringBuffer length vs. capacity. 85 Q# 93. Write a program that demonstrate append() method . 86 Q# 94. Write a program that demonstrate insert() method. 87 Q# 95. Write a program that demonstratereplace() method. 87 Q# 96. Write a program that demonstrate IndexOfDemo () method. 87 Chater#09(Package and inter face) 88 Q# 97. Write a program that that demonstrates package access. Q# 98. Write a program that demonstrates class of one package call in second package. 89 Q# 99. Write a program that demonstrate importing package. 93 Q# 100. Write a program that demonstrate fixed storage in interface. 94 Q# 101. Write a program that demonstrate ? 95 Q# 102. Write a program that ? 96 Q# 103. Write a program that show interface can be extended. 98 Chapter#12 (I/O,APPLET, AND OTHER TOPIC) 88 100 Q# 104. Write a program that read the Character. 100 Q# 105. Write a program that read String. 100 Q# 106. Write a program that create a tiny Text editor. 102 Q# 107. Write a program that demonstrate System.out.write( ). 103 Q# 108. Write a program that demonstrate PrintWriter Class. 104 Q# 109. Write a program that demonstrate a text file. 106 Q# 110. Write a program that demonstrate to copy a text file. 107 Q# 111. Write a program that demonstrate on simple simple Applet method. 109 Q# 112. Write a program that demonstrate instanceof () Operator. 110 3|Page
  5. 5. JAVA & OOPS Manual Q# 113. Write a program that that demonstrate how to use assert.? Chapter#19(The Applet Classes) Q# 114. 113 113 Write a program that demonstrates Applet Skelton. 113 Q# 115. Write a program that demonstrate foreground and background ground color of and out put of String. 115 Q# 116. Write a program that demonstrate simple Banner Applet. 116 Q# 117. Write a program that demonstrate showStatus(). 118 Q# 118. Write a program that demonstrate passing parameter to Applet. 119 Q# 119. Write a program that display code and document bases. 121 Q# 120. Write a program that get code and display HTML file. 122 Chapter#20(Events Handling) 123 Q# 121. Write a program that demonstrate mouse event handler. 123 Q# 122. Write a program that demonstrate key event handler. 125 Q# 123. Write a program that demonstrate an adapter in event handling. 126 Q# 124. Write a program that show how to inner classes uses .? 127 Q# 125. Write a program that demonstrate Anonymous inner class. 128 Chapter # 1 (The Genesis of Java) Q# 1. Write a java program which show hallow word app! public class HelloWorldApp { //this line declare a class name and class definition starts from here public static void main(String args[]) { // line where program main function starts System.out.print(" Hello World! "); this line prints HelloWorldApp! } at this lime program main funcation starts } program where class end Chapter # 2 (An Overview Of Java) Q# 2. Write a java program to display a simple string. class example { // This line declare a class name & the class definition is start from here . public static void main(String a[]) { // This line begins the main() method. System.out.println(" this is a simple program."); //this print this string followed by newline. 4|Page
  6. 6. JAVA & OOPS Manual } } // end of main program //end of class Description : This is a simple java program in which show a string (" this is a simple program.") OUTPUT: Q# 3. Write a simple java program to display a string and perform a simple multiplication. class Example_2{ // This line daclare a new class & the class defination is start. public static void main(String a[]){ // This line begins the main() method. int num; // this declares a variable called num. num=100 ; // this assign num the value 100. System.out.println("this is num: " + num); // this line show output of num //This line outputs the string and number. num=num * 2; // this line show value of num is equals to num multiply by 2 System.out.print("The value of num * 2 is "); //This line outputs the string "The value of num * 2 is " System.out.println(num); // this is a output line which give the value of num //This line output the value store in variable num followed by a new line. } } // end of main prograam // end of class DESCRIPTION:In this program we Ist creat a class with name of example2, after this we initialize num and give the value and show value of num in form of output,after this we declare ―num = num * 2‖And than show thevalue of num after multiplying by 2. OUTPUT: Q# 4. Write a program which demonstrate the if statement.: class IfSample{ // This line daclare a class of name ifSample 5|Page
  7. 7. JAVA & OOPS Manual public static void main(String a[]){ // This line begins the main() method. int x, y; // this declares a variable called num. x=10; // this assign x the value 10. y=20 ; // this assign y the value 20. if(x<y) // in this line we give if Statement that ifx is less than y than give System.out.println("x is less than y"); // This line outputs the string. x= x*2; // multiply x by 2. if(x==y) System.out.println("now x is equal to y"); show a string // this is a output line which x= x*2; //multiply again by 2 if(x>y) System.out.println("now x is greater than y"); show a string // this is a output line which } //end of main program } // end of a class DESCRIPTION: This java program in which we ist make a class of name after making class we initialize x and y and give them value , than we give if condition in which we say if value of x is less than y than show ―x is less than y‖ , Now x multiply by 2 , Now we also give if condition x is equals to OUTPUT: Q# 5. write a program to demonstrate the for loop. class ForTest{ // This line daclare a new class & the class defination is start. public static void main(String a[]){ // This line begins the main() method. int x; //daclare a integer x. for(x=0; x<10; x=x+1) //for loop start System.out.println("this is x: " + x); } // end of main program 6|Page // this line show value of x
  8. 8. JAVA & OOPS Manual } // end of a class DESCRIPTION: In this line I ist initialize x and then give for loop and then show the output line in which I show output line and after this our main program end. OUTPUT: Q# 6. Write a program which contains block of code in “for” loop definition. class blocktest{ // this line declare class name public static void main (String arg []){ // this is the main line were program main funcation starts int x,y; // in this line x and y is declaer as as int variable * y=20; in this line we give thie value of y * for(x=0;x<20;x++) { this is a for loop that code run 20 time* System.out.println("this is x: " + x); this line give us value of x 20 time * System.out.println("this is y :" + y); this line give us value of y 20 time * y=y-2;} this line show out put of y is given by this formula * } this is the end of main } this is the end of class DESCRIPTION: in this we first declare a class as name blocktest, than we initialize x and y, and than we give value of y; after this we initialize for loop and then it give out put line which show x and y, and in program we declare value of y OUTOUT: 7|Page
  9. 9. JAVA & OOPS Manual Chapter # 3: (Data type, Variable and Arays) Q# 7. Write a program to compute distance light travel in 1000 days using long variables. class Light{ // This line daclare a new class & the class defination is start. public static void main(String a[]){ int lightspeed; // This line begins the main() method. //daclare a integer name lightspeed. long days; //daclare a variable days of datatype long. long seconds, distance; lightspeed=186000; //aproximate speed of light n miles per second. days=1000; //specify number of days. seconds=days*24*60*60; //convert to seconds. distance=lightspeed * seconds; //compute distance System.out.print("In " + days); System.out.print(" days lightwill travel about "); System.out.println(distance + " miles."); //print distance in miles. } } DESCRIPTION: This program calculate the speed of light in 1000 days. We take long variable to store the speed of light because inttype is not large enough to hold the desire value. The range of a long is quite large. This makes it useful whrn big whole numbers are needed. 8|Page
  10. 10. JAVA & OOPS Manual OUTPUT: Q# 8. Write a program that calculates the area of a circle, use data type of double. CODE: class Area{ // This line daclare a new class & the class defination is start. public static void main(String a[]){ // This line begins the main() method. double pi, r, b; // daclere three variable of type double. r=12.3993; //radius of circle. pi=3.1416; // value of pi b=pi*r*r; // Declare area formula. System.out.println("Area of the circle is " + b); //This print the area of circle. } } DESCRIPTION: In this program first declare a class name Area and show main program and than I declare pi r and b and delare value of r and pi after we declare how area found after this in system.out.println line it gives us the value of area OUTPUT: Q# 9. Write a program which demonstrate the char data type. CODE: class CharDemo{ // Declare class name as CharDemo. public static void main(String a[]){ // This line begins the main() method. 9|Page
  11. 11. JAVA & OOPS Manual char ch1, ch2; // daclere two character variable. ch1=88; //Declare value of ch1 ch2='Y'; //Declare ch2 is Y System.out.print("ch1 and ch2: "); //print the string. System.out.println(ch1 + " " + ch2); //display both character. } } DESCRIPTION: In this program I take two character variable ch1assigned the value 88 which is the ASCII (and UNICODE) value that corresponds to the letter X. At the end we display both character value. The program displays the following output. OUTPUT: Q# 10. Write a program in which char variables behave like integers. CODE: class CharDemo2{ // This line daclare a class name and a class start from here . public static void main(String a[]){ // This line begins the main() method. char ch1; // daclere a character variable. ch1='X'; // give a charter to ch1 System.out.println("ch1 contains " + ch1); //this line print ch1 ch1++; //increment ch1. System.out.println("ch1 is now " + ch1); //print incremented character. } } //end of main funcation //end of class DESCRIPTION:In this program I ist make a class of name Chardemo2. In second line main funcation of programme start, after this I initiliaze and declare ch1,after this we print ch1 , then increment in value of ch1 and print value of ch1 OUTPUT: 10 | P a g e
  12. 12. JAVA & OOPS Manual Q# 11. Write a program which demonstrate dynamic initialization. class Square{ // This line daclare a class ‖Square‖& the class is start from here . public static void main(String a[]){ // This line begins the main() method. double x=3.0, y=4.0; // Initiallize two double variables. double z=Math.sqrt(x*x + y*y); //z is initialized and declare calue of z System.out.println("Hypotenuse is " + c); } } //this line print value of Hypotenus // end main funcation end of class name DESCRIPTION: This program computes the length of the hypotenuse of right triangle given the length of two opposing sides. OUTPUT: Q# 12. Write a program that demonstrates the Boolean type values. CODE: class BoolTest{ // This line daclare a new class & the class defination is start. public static void main(String a[]){ // This line begins the main() method. boolean b; // daclere a boolean variable. b=false; //Initialize b is false. System.out.println("b is " + b); // display b . b=true; //now b initialize is true. 11 | P a g e
  13. 13. JAVA & OOPS Manual System.out.println("b is " + b); // display it. if(b) System.out.println("this is executed. "); // if condition is true then this string is print b=false; // b again false. if(b) // initialize if condition System.out.println("this is not executed. "); //this line is not display because b is false. System.out.println("10 > 9 is " + (10>9)); //out come relational operator Boolean which is true } //end of main function } // end of a class DESCRIPTION: I OUTPUT: Q# 13. Write a program which show the effect of nested scopes. CODE: class Scope{ // This line daclare a new class & the class defination is start. public static void main(String a[]){ // This line begins the main() method. int x; // initialize x x=10; //Declare value of x. if(x==10){ //start new scope int y=20; //this y is known only to this block. System.out.println("x and y : " + x + " " + y); // This line show the output x=y*2; // this line show x equals to y*2 12 | P a g e
  14. 14. JAVA & OOPS Manual } // this line show the finishing of block //y=100; // error! y not known here. System.out.println("x is " + x); this line show the output output } // this line show the end of program } this line show the end of class DESCRIPTION:This program shows the scope of any variable. As the comment indicate we Ist declare the class and then initialize and delare OUTPUT: Q# 14. Write a program to demonstrates the lifetime of a variable. class LifeTime{ // This line daclare a class name public static void main(String a[]){ // This line begins the main() method. int x; // daclare a variable x. for(x=0; x<3; x++){ //Declare for loop int y=-1; //y is initialized each time block is entered. System.out.println("y is: " + y); this is a output line y=100; Give value to y System.out.println("y is now: " + y); // this is the output line } // end of loop function } // this line show the main program } DESCRIPTION:In this program we First declare declare a class name oLifetime than main program start , I declare first x and and than declare for loop ; after this after this I initilaze y and print value of y; after again give value to y and print again value of y OUTPUT: 13 | P a g e
  15. 15. JAVA & OOPS Manual Q# 15. Write a program that convert one data type in to another data type class Conversion { // Declare class name public static void main(String args[]){ of program start from here int i = 257; byte b; //daclre main line line of program main body //Initialize and Declare i //initialize b double d = 323.42; //Initialize and Declare d System.out.println("n Conversion of int tom byte."); b = (byte) i; // print string line // convertion of data type System.out.println(" i and b is "+ i + " " + b); // print value of I and b System.out.println( "n Conversion od double to int " ); //print string line i = (int) d ; // convertion of data type System.out.println("d and i " + i + " " + d ); // print value of I and d System.out.println("n Conversion of double to byte"); b = (byte) d; // print string line // convert value of b in to byte System.out.println("d and b " + d + " " + b); print value of b and d } // end of main program } // end of class Description: In this program first make a class and write it main main method after intiliaze I, b, d. after we conert one data type in to another data type and prind their value Output: 14 | P a g e
  16. 16. JAVA & OOPS Manual Q# 16. Write a program that multiply and add different data type variable. class Promote { // class name start from here public static void main (String args [ ] ) { // Main body of program start from here byte b = 42; //Initialize and declare b char c='a'; //Initialize and declare c short s = 1024;//Initialize and declare s int i = 50000; //Initialize and declare I float f = .67f; //Initialize and declare f double d = .1234; //Initialize and declare d double result = (f * b) + (i / c) + (d * s); //Initialize and declare result System.out.println((f * b) + " " + (i / c) + " "+ (d * s)); System.out.println("result = " + result); } } // print line // print result // end of main programme // end of a class Description: In this program I first make class and write its main method after this I declare and initialize b, c, s, I, f, d. after this initialize result and give a value after we print our result Output: Chapter # 4 (Operator) Q# 17. Write a program which demonstrate the arithmetic operator class BasicMath{ // This line daclare a new class & the class defination is start. public static void main(String a[]){ // This line begins the main() method. System.out.println("Integer Arithmetic"); //arthmetic using integers int x=1+1; //store 2 in variable x int b=x * 3; //x multiply a by 3 and store in b. int c=b/4; //b divide b by 4 and store in c. int d=c - x; // c minus x and store in d int e=-d; // minus of d is System.out.println("a = " + x); // print value of a System.out.println("b = " + b); // print value of b 15 | P a g e
  17. 17. JAVA & OOPS Manual System.out.println("c = " + c); // print value of c System.out.println("d = " + d); // print value of d System.out.println("e = " + e); // print value of e System.out.println("nFloating Point Arithmetic"); // Arthmetic using doubles double da=1+1; //store 2 in variable da double db=da * 3; //multiply da by 3 and store in db. double dc=db/4; //divide db by 4 and store in dc. double dd=dc - da; // value of dc minus da store in dd double de=-dd; // value of dd store in de System.out.println("da = " + da); // print value of da System.out.println("db = " + db); // print value of db System.out.println("dc = " + dc); // print value of dc System.out.println("dd = " + dd); // print value of dd System.out.println("de = " + de); // print value of de } // end of main method } // end of class DESCRIPTION: in this programme first make a class and write its main method, after intilize and declare a, b, c, d, e. and da, db, dc, dd, and print their value . OUTPUT: Q# 18. Write a programme that demonstrate modulus operator class modulas{ // class name public static void main(String arg []){ int x=67; double y=67.25; //initialize and declare x //initialize and declare y System.out.println("x mod 10 = " + x%10 ); System.out.println("y mod 10 = " + y%10 ); } // end main method 16 | P a g e // main method //print modulus of x //print modulus of y
  18. 18. JAVA & OOPS Manual } end class Description:in this programme first make a class and write its main method than initialize and declare c and y and print them. Output: Q# 19. Write a program in which various assignment operator is used. //Demonstrate several assignment operator class OpEquals{ // class name public static void main(String a[]){ // This line begins the main() method. int i=1; // declare i int b=2; // Declare b int c=3; // Declare 3 i+=5; // increment 5 in i. b*=4; //multiply b by 4 than again store in b. c+=i*b; //I multiply with b and add in c c%=6; // modulus of c. System.out.println("i = " + i); // print value of i System.out.println("b = " + b); // print value of b System.out.println("c = " + c); // print value of c } } end main method // end the class Description: in this programme first make a class and write its main method initialize and declare a, b , c and again declare a, b, c and print their value Output: 17 | P a g e
  19. 19. JAVA & OOPS Manual Q# 20. Write a program which shows the function of increment(++). class InDec{ // Class name and class start from here. public static void main(String a[]){ // main method of program line. int a=1; // Initialize1 in variable a. int b=2; // Initialize 2 in variable b. int c, d; // daclare two variables c & d. c=++b; // increment in b than store in c. d=a++; // store value of a in d. than increment in i. System.out.println("a = " + i); //this print the value i. System.out.println("b = " + b); //this print the value b. System.out.println("c = " + c); //this print the value c. System.out.println("d = " + d); //this print the value d. } } DESCRIPTION: In this program two variable initialized and other two variables are initialized by increment in values of pervious two variables. OUTPUT: Q# 21. Write a programme left shifting the byte value. class ByteShift { // class name public static void main (String args [ ] ) { from here byte a = 64, b; int i; //Declare a // declare i i = a<<2; b = (byte) (a << 2); 18 | P a g e //Decare i is lessthan 2 // convert data type // main body of programme start
  20. 20. JAVA & OOPS Manual System.out.println("orignal value of a: " +a); //print value of a System.out.println("i and b:" + i + " " + b); } // print value of i and b // main of main programme } //end of class Description: Output: Q# 22. Write a programme that demonstrate the Boolean logical operator class BoolLogic { // calss name public static void main (String args[]) { // main method of programme boolean a=true; // Declare a boolean b=false; //Declare b boolean c=a | b; //Declare c boolean d=a & b; //Declare d boolean e=a ^ b; //Declare e boolean f=(!a & b) | (a & !b); boolean g= !a; //Declare f //Declare g System.out.println(" a = " + a); //Print value of a System.out.println(" b = " + b); //Print value of b System.out.println(" a|b = " + c); //Print value of c System.out.println(" a&b = " + d); //Print value of d System.out.println(" a^b = " + e); //Print value of e System.out.println(" (!a & b) | (a & !b) = " + f); System.out.println(" !a = " + g); } } //Print value of g //main body of programme ended // class ended Description: Output: 19 | P a g e //Print value of f
  21. 21. JAVA & OOPS Manual Q# 23. Write a program which demonstrates the ? operator. class Ternary{ // Declare class name public static void main(String a[]){ // Main body of programme start from here. int i, k; // daclare two variables i & k. i=10; // Initialize i k= i<0 ? -i : i; //get absolute value of i. System.out.print("Absolute value of "); // print string line System.out.println(i +" is "+ k); //this print the value of i and k. i=-10; // Initialize k= i<0 ? -i: i; // get absolute value of i. System.out.print("Absolute value of "); // print string line System.out.println(i +" is "+ k); //this show the value of i and k. } // Main body of programme ended } // class ended DESCRIPTION:This program shows the functionality of ? operator. In this programme ist declare two variable and initialize them than print their value after this again initialize both variable and print their value. OUTPUT: Chapter # 5 (Control Statement) Q# 24. Write a programme that demonstrate if-else statement class IfElse{ // This line daclare a new class & the class defination is start. public static void main(String a[]){ // This line begins the main() method. 20 | P a g e
  22. 22. JAVA & OOPS Manual int month=4; //April String season; //daclare a string name season. if(month==12 || month==1 || month==2) season= "winter"; //if above condition is true than print winter. else if(month==3 || month==4 || month==5) season= "Spring"; //if above condition is true than print Spring. else if(month==6 || month==7 || month==8) season= "Summer"; //if above condition is true than print Summer. else if(month==9 || month==10 || month==11) season= "Auntumn"; //if above condition is true than print Auntumn. else season="Bogus Month"; // System.out.println("April is in the " + season + "."); // this print the season of month. } } // end of main programme // end of class DESCRIPTION: This java program demonstrates if-else-if statements. The if statements are executed from the top down. In above if one of the condition is true the statement associated with that if is executed and rest of the ladder is bypassed. If none of the condition is true then final else statements is executed. OUTPUT: Q# 25. Write a programme that show simple example of switch class SwitchSample{ // class definition start from here. public static void main(String a[]){ // Main body of programme start from here for(int i=0; i<6; i++) // for loop start. switch(i) { //start body of switch statment case 0: //if i=0 than this case is executed. System.out.println("i is zero."); 21 | P a g e
  23. 23. JAVA & OOPS Manual break; // this stop the execution and end the program case 1: //if i=1 than this case is executed. System.out.println("i is one."); break; // this stop the execution and end the program case 2: //if i=2 than this case is executed. System.out.println("i is two."); break; case 3: // this stop the execution and end the program //if i=3 than this case is executed. System.out.println("i is three."); break; default: // this stop the execution and end the program. //if i is greater than t than default statment executed. System.out.println("i is greater than 3."); } } } DESCRIPTION: This java program demonstrates the switch statement. In above program as you can see each time through the loop the statements associated with the case constant that matches i are executed. All others are bypassed. After i is greater than 3 no case statements match so the default statement is executed. OUTPUT: Q# 26. Write a programme that show in switch break statements are optional class MissingBreak{ // class name . public static void main(String a[]){ // Main body of programme start from here. for(int i=0; i<8; i++) // for loop start. switch(i){ //start body of switch statment case 0: case 1: case 2: 22 | P a g e
  24. 24. JAVA & OOPS Manual System.out.println("i is less than 3"); break; // print the string // this line break the loop case 3: case 4: System.out.println("i is less than 5"); break; default: // this line break the loop //if no condition is true then this is executed. System.out.println("i is 6 or more"); } } } // print the string // print the string // for loop ended // main body of programme ended // class ended Description: In this program we see that if break statements are not used then the program will not stop and it print the statements following by true case. In above case 0,1 and 2 a single statement is executed 3 then break statement is executed and control is bypassed. At the end if no condition is true then the default statement is executed. Output: Q# 27. it. Write a programme that show the season when any month is given to class Switch { // class name declare public static void main(String args[]) { // public main method declared int month = 4; // variable (month) is declared of int type, value is 4 String season; // another variable (season) is declared switch (month) { //body of switch satement start case 12: case 1: case 2: season = "Winter"; break; 23 | P a g e // break statement use to jump from the switch
  25. 25. JAVA & OOPS Manual case 3: case 4: case 5: season = "Spring"; break; case 6: case 7: case 8: season = "Summer"; break; case 9: case 10: case 11: season = "Autumn"; break; default: season = "Bogus Month"; } //end of switch statement System.out.println("April is in the " + season + "."); // here show the final output of program } } //main body of programme ended // class ended Description:In this programme first declare a class name than write its main method than declare month and season after this declare switch statement and then write the cases .after this print the season of April. Output: Q# 28. Write a programme that demonstrate the while loop //Demonstrate the while loop 24 | P a g e
  26. 26. JAVA & OOPS Manual class While { // Declare class name public static void main (String args [ ] ) { // main body of class start from here int n = 10; // declare n while(n > 0) { // start while loop System.out.println(―tick‖ + n) ; n--; } } } //print value of n // Decrement n // loop body ended // main body ended //class ended Description: In this programme first make class and then main body of programme start and then declare while loop after this print the value of n after decrement the n. Output: Q# 29. Using while loop write a program which display midpoint of two numbers. class NoBody { // class name is declared as Nobody public static void main(String args[]) { // public main method declared int i, j; // two variables i & j are declared i = 100; j = 200; // intialize i and j. // find midpoint between i and j while(++i < --j) ; // Declare while loop System.out.println("Midpoint is " + i); // show output } } // main body of programme start from here // class ended Description: 25 | P a g e
  27. 27. JAVA & OOPS Manual In this programme first declare a class name as NoBody then main body of programme start than declare I and j after this giv value to I and j and declare while loop after this print value of I. Output: Q# 30. Write a programme that demonstrate dowhile class DoWhile { // Class name is as DoWhile public static void main(String args[]) { // public main method is start. int n = 10; // variable (n) is declared of int type, value is 10. do { // do whilel loop is started here. System.out.println("tick " + n); n--; // print value of n // decrement in n. } while(n > 0); // this loop is stop when n is equal to or less than zero. } // main body programme ended } //class ended Description: In this programme first make a class and then write its main method after this declare n equals to ten than apply do and print line after write while condition , In this programme do while loop is used . Q# 31. Write a program using do-while to process a menu selection. class Menu { public static void main(String args[]) throws java.io.IOException { input errors char choice; do { 26 | P a g e // This line is used for for handling exception and //Declare char as a choice //
  28. 28. JAVA & OOPS Manual System.out.println("Help on:"); // print Help on: System.out.println(" 1. if"); // print 1.if System.out.println(" 2. switch"); // print 2.Switch System.out.println(" 3. while"); //print 3.While System.out.println(" 4. do-while"); // print 4. DO while System.out.println(" 5. forn"); //print 5 for n System.out.println("Choose one:"); // print choose one choice = (char) System.in.read(); // char are read from this method } while( choice < '1' || choice > '5'); // Apply while loop System.out.println("n"); switch(choice) { // Switch statement start case '1': // this is condition one System.out.println("The if:n"); // print the if:n System.out.println("if(condition) statement;"); // print if condition statement System.out.println("else statement;"); //print else statement break; // This line break the switch statement case '2': //This is condition 2 System.out.println("The switch:n"); // print the switch System.out.println("switch(expression) {"); // print switch System.out.println(" case constant:"); // print case constant expression System.out.println(" statement sequence"); // print statement sequence System.out.println(" break;"); System.out.println(" // // print break ..."); // print dotted line System.out.println("}"); print ending braes break; // This line break the switch statement case '3': // This is condition three System.out.println("The while:n"); //print the while System.out.println("while(condition) statement;"); // print while condition statement 27 | P a g e
  29. 29. JAVA & OOPS Manual Break; //This line break the switch statement case '4': // this is condition four System.out.println("The do-while:n"); // this print the which in inverted commas System.out.println("do {"); // this print the which in inverted commas System.out.println(" statement;"); // this will print Staement System.out.println("} while (condition);"); // this line print} while (condition); break; // this ill break the switch statement case '5': // this is choice 5 System.out.println("The for:n"); //print the for System.out.print("for(init; condition; iteration)"); print for(init; condition; iteration) System.out.println(" statement;"); break; // print Statement } } } // switch statement ended // main body of programme ended // class ended DESCRIPTION: In this program we first make a class and then write main body of programme in which we print some condition than call System.in.read()ask input from user at run time after this we give detail of our choice which is given by user. Output: 28 | P a g e
  30. 30. JAVA & OOPS Manual Q# 32. for Write a programme that demonstrate loop control veriable inside the class ForTick { // class start from here public static void main (String args [] ) { // main body of programme // here n is declared inside the loop For(inr n =10; n>0;n--) { // Define for loop System.out.println(―tick ‖ + n); } } } // this brace show end of loop body // this brace show end of main body of programme // this brace show end of class Description: In this programme first make a class and then start main body of programme than declare for loop and print out put Q# 33. Write a program in which for loop is used and find the prime number by using this loop. class FindPrime { //class name start . public static void main(String args[]) { // This line begins the main() method. int num; //daclare a variable of type int. boolean isPrime = true; //initialize a boolean variable. num = 30; // give value to num for(int i=2; i <= num/2; i++) { //for loop body is started. if((num % i) == 0) { //this find prime number. isPrime = false; // declare isPrime is equals to false break; // if condition stop } // if condition ended } loopbody ended if(isPrime) 29 | P a g e
  31. 31. JAVA & OOPS Manual System.out.println("Prime"); // print prime else //else is uses System.out.println("Not Prime"); // print Not Prime } } // main body of programme ended // this brace show end of class DESCRIPTION: In this program for loop is used. Take an integer 30 and take modulus with 2 if it is equal to zero it is prime otherwise it display not prime. As we know 30 is not aprime number it display not prime. It display the following output. Output: Q# 34. Write program in which two variable used to control the iteration of for loop class Sample { // class name start public static void main(String args[]) { // This line begins the main() method. Int x, y; //declare two integer variables. Y = 4; // give value to 4 for(x=1; x<y; x++) { // for initialize declare System.out.println(―x = ― + x); //this print the value of x. System.out.println(―y = ― + y); //this print the value of y. y--; // Decrement y } // for loop ended } //main body of programme ended } // class ended DESCRIPTION: In this program make class than start main method after this x and y after this for loop is started and then print the value of x and y and decrement y. Output: 30 | P a g e
  32. 32. JAVA & OOPS Manual Q# 35. Write program in which two variable used to control the iteration of for loop using for comma class comma { // class body start from here public static void main (String args []) { Int a , b; // main body of programme start from here // Declare a aand b For(a=1, b=4; a<b; a++, b--) { // use for loop System.out.println(―a= ‖ = + a) ; // print value of a System.out.println(―b= ― + b); // print value of b } } } loop body ended main body ended class ended Description: In this programme first declare a class than write main method and initiliaze a and b and declare for loop after this print value Output: Q# 36. Write a for loop program in which initialization and iteration is moved out of the for loop. class ForVar{ // class name start from here public static void main(String args[]) { // This line begins the main() method. int n; // declare n boolean done= false; //initialize a boolean variable. n=0; // put n equals to zero for(; !done;){ ///this is infinte loop .no condition & iteration System.out.println("n is " + n); // print value of n if(n==5) done=true; // declare if statement n++; //if above condition is true than increment in n. } // end of loop } // end of main body } // end of class DESCRIPTION: In this program the for loop is empty e.g no condition and iteration. Q# 37. Write a program of nested for loop. class Nested { // This line daclare a class name public static void main(String args[]) { // This line begins the main() method. 31 | P a g e
  33. 33. JAVA & OOPS Manual int i, j; //daclare two integer variable. for(i=0; i<10; i++) { //first loop for(j=i; j<10; j++) //2nd loop System.out.print("."); // this line print dotted line System.out.println(); } // loop body ended } // main body of program ended } // class ended DESCRIPTION: This is the program in which nested for loop is used. Output: Q# 38. Write a program in using break to exit a loop. class BreakLoop { // This line daclare a new class & the class defination is start. public static void main(String args[]) { // This line begins the main() method. for(int i=0; i<100; i++) { //loop body start. if(i == 10) break; // terminate loop if i is 5 System.out.println("i: " + i); ///print value of i. } System.out.println("Loop complete."); //Print this string. } } DESCRIPTION: In this program for loop is designed to run from 0 to 99 the break statement causesit to terminates when i equals 10. Output: 32 | P a g e
  34. 34. JAVA & OOPS Manual Q# 39. Write a program in which using a break to exit a while loop. class BreakLoop2 { // This line daclare class name public static void main(String args[]) { // This line begins the main() method. int i = 0; // declare I =0 while(i < 100) { //while loop body start. if(i == 10) break; // terminate loop if i is 10 System.out.println("i: " + i); //print value of i. i++; } System.out.println("Loop complete."); } } DESCRIPTION: the break statement can be used in any of java’loop. In above while loop is used and loop is designed to run from 0 to 99, the break statement causes it to terminates early when i equal 10. OUTPUT: 33 | P a g e
  35. 35. JAVA & OOPS Manual Q# 40. Write a program in which using a break to exit a while loop. class BreakLoop3 { // This line daclare a new class & the class defination is start. public static void main(String args[]) { // This line begins the main() method. for(int i=0; i<3; i++) { //first for loop start. System.out.print("Pass " + i + ": "); for(int j=0; j<100; j++) { //2nd loop start. if(j == 10) break; // terminate loop if j is 10 System.out.print(j + " "); //print value of j. } System.out.println(); } System.out.println("Loops complete."); } } DESCRIPTION: In this program first loop run 3 times and internal loop is designed to run 0 to 99 but it stop due to break statement when j equals 10. This program shows the following output. OUTPUT: Q# 41. Write a program in which break is used like go to statement. class Break { // This line daclare a new class & the class defination is start. public static void main(String args[]) { // This line begins the main() method. boolean t = true; //initialize a boolean variable. first: { //body of first block start second: { //body of 2nd block start third: { //body of third block start System.out.println("Before the break."); 34 | P a g e
  36. 36. JAVA & OOPS Manual if(t) break second; //break out of second block. System.out.println("This won't be execute."); } System.out.println("This won't be execute."); } System.out.println("This is after second block."); } } } DESCRIPTION: This is the program in which break statement work like a goto. In this statement of third block print after this second block is break and statement of first block is executed. OUTPUT: Q# 42. Write a program that used for a labelled break statement to exit from nested loop. class BreakLoop4 { // class definition starts public static void main (String args []) { outer: for(int i = 0; i<3 ; i++) { // main body of program start from here // for loop declared System.out.print("Pass" + i + ": "); // print value of for(int j=0; j<100;j++) { if (j == 10) break outer; // declared if condition j equals to 10 // exit both loops System.out.print(j + " "); // print j } //second loop body ended System.out.println("This will not print"); 35 | P a g e // Again for loop declared
  37. 37. JAVA & OOPS Manual } // first loop body ended System.out.println("Loops Complete."); // print loop completed } } // main body ended // class ended Q# 43. Write a program that uses continue to cause two number. class Continue { // clss defination start public static void main (String args [ ] ) { for (int i = 0; i < 10; i++ ) { // main body of program start // for loop started System.out.print(i + " "); // print value of i if(i%2 == 0) continue; // print modulas of 2 System.out.println(" "); // print nothing } } } //loop body ended // main body of program ended // class ended Description: In this program first make a class than make main method than initialize for loop than print I after get modulas and print Output: Q# 44. Write a program that uses continue to print a triangular multiplication of table for 0 through 9. class ContinueLable { // class definition start public static void main (String args [] ) { outer: for(int i=o; i<10; i++) for(int j=0; j<10; j++) if (j > i) { //main body of program start from here { for loop declare { again for loop declare // if j is greater than i System.out.println(); continue outer; } 36 | P a g e // print nothing // print // if condition finished
  38. 38. JAVA & OOPS Manual System.out.print(" " + (i * j)); } } // print value of i*j // first for loop declared // second for declared System.out.println(); } // main body of program ended } // class ended Description: In this program Output: Q# 45. Write a program that demonstrates return. class Return { // class name declared public static void main (String args []) { boolean t = true; t declared as a boolean type System.out.println("Before the return. "); if(t) return; // main body of program start // print before the return // return to caller System.out.println("This Won't execute. "); // print this won’t execute } } // main body of program ended class ended Description: In this program first make a class name than write main method after declare t as Boolean type after this print string after this if condition apply after print this won’t execute. Output: 37 | P a g e
  39. 39. JAVA & OOPS Manual Chapter # 6 (Introducing classes) Q# 46. Write a program that call this file BoxDemo.java. class Box { double width; double height ; double depth; } class BoxDemo{ public static void main (String args [ ] ){ Box mybox=new Box (); double vol; mybox.width=10; mybox.height=15; mybox.depth=18; vol=mybox.width*mybox.height*mybox.depth; System.out.println("Volume of Box is " + vol ); } } Description: In this program Output: Q# 47. Write a program that declares two Box object. class Box { double width; double height; double depth ; } class BoxDemo2{ public static void main (String args [] ) { 38 | P a g e
  40. 40. JAVA & OOPS Manual Box mybox = new Box (); Box mybox2 =new Box (); double vol; mybox.width=10; mybox.height=20; mybox.depth=15; mybox2.width=10; mybox2.height=15; mybox2.depth=18; vol=mybox.width*mybox.height*mybox.depth; System.out.println(" Volume of Box is " + vol ); vol=mybox2.width*mybox2.height*mybox2.depth; System.out.println(" Volume of Box is " + vol ); } } Description: Output: Q# 48. Write a program that includes a method inside the box class. class Box { //declare class name double width; // initialize width double height; // initialize height double depth; // initialize depth void volume ( ) { // declared volume method System.out.println("Volume of Box is :"); //print string System.out.println(width*height*depth); print volume } // end of volume method } // end of class class BoxDemo3{ // declare class name public static void main (String args [ ]) { Box mybox=new Box (); 39 | P a g e // main body of program start // declare a memory of for new box mybox
  41. 41. JAVA & OOPS Manual Box mybox2=new Box (); // declare a memory of for new box mybox //assign value to mybox’s instance variable mybox.width=15; // give value of heightof second box mybox.height=18; // give value of heightof second box mybox.depth=23; //give value of depthof second box //assign different value to mybox2’s instance variable mybox2.width=10; // give value of width of second box mybox2.height=13; // give value of heightof second box mybox2.depth=15; //give value of depthof second box mybox.volume(); //display the volume of first box mybox2.volume(); //display the volume of Second box } } Description: Output: Q# 49. Write a program that volume () returns the volumeof a box class Box { double width; double height; double depth; double volume() { return width * height * depth; } } class BoxDemo4{ public static void main (String args [ ]) { Box mybox1=new Box (); Box mybox2=new Box (); double vol; 40 | P a g e
  42. 42. JAVA & OOPS Manual mybox1.width=15; mybox1.height=18; mybox1.depth=23; mybox2.width=10; mybox2.height=13; mybox2.depth=15; vol=mybox1.volume(); // declare vol System.out.println("Volume of mybox1 is:" + vol); vol=mybox2.volume(); // print volume of myBox1 // declare vol System.out.println("Volume of mybox2 is: " + vol); mybox2 } // print volume // ending brace of main body } // ending brace of main class Description: In this program first make a super a class class and in which declare widthheight and depth after this make a volume method after this make main class in which our main method is call after this declare mybox1 and mybox2, after this declare vol after this assign values different values to mybox1 and mybox2, after this print volume of box 1 and 2. Output: Q# 50. Write a program that use as parameterized method class Box { // declare class name double width; // declare width double height; // declare height double depth; // declare depth double volume() { // declare volume function return width * height * depth; // this line return value of volume } void setdim(double w, double h, double d ) { width=w; 41 | P a g e //declare width // setdim method initialize
  43. 43. JAVA & OOPS Manual height=h; // declare h depth=d; // declare depth } } // ending brace of stdim // ending brace of class class BoxDemo5{ //Declare class name public static void main (String args [ ]) { // main body of program Box mybox1=new Box (); // Declare myBox1 Box mybox2=new Box (); // Declare mybox2 double vol; // Declare vol mybox1.setdim(10, 16, 19 ); // declare value of mybox1 mybox2.setdim(9, 10,15); // declare value of mybox2 vol=mybox1.volume(); // Initialize vol System.out.println("Volume of mybox1 is " + vol); vol=mybox2.volume(); // Initialize vol System.out.println("Volume of mybox2 is " + vol); } // print volume of mybox1 // print volume of mybox2 // ending brace of main body } // ending brace of class Description: Output: Q# 51. box. Write a program that use a constructor to initialize the dimension f a class Box { double width; double height; double depth; Box( ) { System.out.println("costructing box is "); width=17; height=19; depth=15; 42 | P a g e
  44. 44. JAVA & OOPS Manual } double volume() { return width * height * depth; } } class BoxDemo6{ public static void main (String args [ ] ){ Box mybox1=new Box(); Box mybox2=new Box(); double vol; vol=mybox1.volume(); System.out.println("volume is " + vol); vol=mybox2.volume(); System.out.println("volume is " + vol); } } Description: Output: Q# 52. Write a program that uses a parameterized constructor to initialize the dimension. class Box { double width; double height; double depth; Box(double w, double h, double d ) { width=w; height=h; depth=d; } 43 | P a g e
  45. 45. JAVA & OOPS Manual double volume() { return width * height * depth; } } class BoxDemo7{ public static void main (String args [ ] ){ Box mybox1=new Box(17,19, 23); Box mybox2=new Box(24, 27, 30); double vol; vol=mybox1.volume(); System.out.println("volume is " + vol); vol=mybox2.volume(); System.out.println("volume is " + vol); } } Description: Output: Q# 53. Write a program that defines an integer stack that can hold 10 values. class Stack { int stack [] = new int [10]; int tos; Stack ( ) { // Initialize top-of-stack tos = -1; } void push (int item) { // push an item on to stack if (tos == 9) System.out.println("Stack is full."); else 44 | P a g e
  46. 46. JAVA & OOPS Manual stack[++tos] = item; } int pop ( ) { // pop an item from stack if (tos < 0) { System.out.println("Stack underflow"); return 0; } else return stack[tos--]; } } class TestStack { public static void main (String args [ ]) { Stack mystack1 = new Stack(); Stack mystack2 = new Stack(); for(int i =0 ; i < 10; i++) mystack1.push(i); // push some number on to stack for (int i = 10; i<20; i++) mystack2.push(i); // push some number on to stack System.out.println("Stack my skack1 :"); for (int i = 0; i<10; i++) System.out.println(mystack1.pop()); System.out.println("Stack my skack2 :"); for (int i = 0; i<10; i++) System.out.println(mystack2.pop()); } } Description: In this program first make a class name as stack after this declare Stack and tos . after this I make a constructor in which I initialize top-of-stack than make push method in which define if tos equals to 9 than show shack is ful otherwise push another number. After this declare pop method in which define if tos lessthan 0 than show stack underflow and ant return 0 otherwise decrease number. After this make a main class and in main class declare two Object mystack1 and mystack2 after this declare for loop than print output. Output: 45 | P a g e
  47. 47. JAVA & OOPS Manual Chapter # 7 (A Closer Look at Methods and Classes) Q# 54. Write a program that demonstrates method overloading. class OverloadDemo{ void test() { // declare class name // declare test method System.out.println("No parameters"); } // print no parameter // ending brace of test method void test (int a ) { // declare test method again System.out.println("a is : " + a ); } // print value of a // ending brace of test method void test (int a, int b) { // declare test method again System.out.println("a and b is " + a +" " + b); } // print value of a and b // ending brace of test method double test(double a) { // declare test method again System.out.println("double a : " + a); return a*a; } // print value of a // return value of a*a // ending brace of test method } // ending brace of class class Overload{ // declare class name public static void main (String args [ ] ){ OverloadDemo ob = new OverloadDemo (); 46 | P a g e // main method call // declare new object as ob
  48. 48. JAVA & OOPS Manual ob.test(); // class test method ob.test(10); // class test method ob.test(10 , 20 ); // class test method double result = ob.test(123.456); // declare result System.out.println ("Reslult of ob.test(123.456) is :" + result ); value of result } } // print // ending brace of main body // ending brace of main class Description: In this program first declare class name than test name method define again and again . after this make a main class and after this make a new object ob after this call method function with object ob than initialize result after this print value of result. Output: Q# 55. Write a program that use overloaded method and convert a parameter into corresponding data type when compatible type of constructor is not available. class OverloadDemo{ void test() { System.out.println("No parameters"); } void test (int a, int b) { System.out.println("a and b is " + a +" " + b); } void test(double a) { System.out.println("Inside test (double) a : " + a); } } class Overload2{ public static void main (String args [ ] ){ OverloadDemo ob = new OverloadDemo (); int i = 88; 47 | P a g e
  49. 49. JAVA & OOPS Manual ob.test(); ob.test(10, 20); ob.test(i); ob.test(123.456); } } DESCRIPTION: In this program as you can see that this program is same as previous one. But the difference is that we are calling a constructor which has one parameter of integer type but in the constructor overloading we has no one like this. At this time java automatically converts data type into most corresponding data type as here integer into double. Keep in mind that both have same number of parameters. OUTPUT: Q# 56. Write a program that shows the dimension of a box in various way. class Box { double width; double height; double depth; Box(double w, double h, double d ) { width=w; height=h; depth=d; } Box () { width=-1; height=-1; depth=-1; } Box(double len) { width=height=depth=len; } 48 | P a g e
  50. 50. JAVA & OOPS Manual double volume () { return width*height*depth; } } class OverloadCons { public static void main (String args [ ] ) { Box mybox1=new Box(17,19, 23); Box mybox2=new Box(); Box mybox3=new Box(); double vol; vol=mybox1.volume(); System.out.println("Volume of box1 is :" + vol); vol=mybox2.volume(); System.out.println("Volume of box2 is :" + vol); vol=mybox3.volume(); System.out.println("Volume of box3 is :" + vol); } } Description: Output: Q# 57. Write a program that class Test{ // declare int a, b; Test(int i, int j ) { a=i; b=j; } boolean equals(Test o) { if 49 | P a g e
  51. 51. JAVA & OOPS Manual (o.a == a && o.b == b ) return true; else return false; } } class PassOb { public static void main (String args [ ] ) { Test Ob1 = new Test( 100, 22 ); Test Ob2 = new Test( 100, 22 ); Test Ob3 = new Test( -1, -1); System.out.println("ob1 == ob2 " + Ob1.equals(Ob2)); System.out.println("ob1 == ob3 " + Ob1.equals(Ob3)); } } Description: Output: Q# 58. Write a program that shows the overloading of constructors. class Box { // declare class name double width; // declare width double height; // declare height double depth; // declare depth Box(Box ob ) { // make constructor width=ob.width; height=ob.height; depth=ob.depth; } // ending brace of constructor Box(double w, double h, double d ) { width=w; 50 | P a g e
  52. 52. JAVA & OOPS Manual height=h; depth=d; } Box () { width=-1; height=-1; depth=-1; } Box(double len) { width=height=depth=len; } double volume () { return width*height*depth; } } class OverloadCons2 { public static void main (String args [ ] ) { Box mybox1=new Box(10,120, 15); Box mybox2=new Box(); Box mycube=new Box(7); Box myclone=new Box(mybox1); double vol; vol=mybox1.volume(); System.out.println("Volume of mybox1 is " + vol ); vol=mybox2.volume(); System.out.println("Volume of mybox2 is " + vol ); vol=mycube.volume(); System.out.println("Volume of mybox3 is " + vol ); vol=myclone.volume(); System.out.println("Volume of clone is " + vol ); } } 51 | P a g e
  53. 53. JAVA & OOPS Manual Description: Output: Q# 59. Write a program that is passed by value. class Test { void meth (int i, int j ) { i *=2; j /=2; } } class CallByValue { public static void main (String args [ ] ) { Test ob = new Test ( ); int a = 15; int b = 20; System.out.println("a and b before call :" + a + " " + b ); ob.meth(a, b); System.out.println("a and b after call :" + a + " " + b ); } } Description: In this program we settle a method in a class named as test and then perform some operations on the variables in the method then call that method in the main function and display them using System.out.println() method. We can see that when we call parameters by value our operations will not perform on them. It just prints them as it is. Output: 52 | P a g e
  54. 54. JAVA & OOPS Manual Q# 60. Write a program that is call by reference. class Test { int a, b; Test (int i, int j ) { a = i; b = j; } void meth(Test o ) { o.a *= 2; o.b /= 2; } } class CallByRef { public static void main (String args [ ] ) { Test ob = new Test (15, 20 ); System.out.println("a and b before call :" + ob.a + " " + ob.b ); ob.meth(ob); System.out.println("a and b after call :" + ob.a + " " + ob.b ); } } Description: : In this program we settle a method in a class named as test and then perform some operations on the variables in the method then call that method in the main function and display them using System.out.println() method. We can see that when we call parameters by reference our operations will perform on them. It prints them after operating on them according to the operators Output: Q# 61. Write a program that returning an object. class Test{ int a; Test(int i) { 53 | P a g e
  55. 55. JAVA & OOPS Manual a=i; } Test incByTen () { Test temp = new Test (a+ 10 ); return temp; } } class Retob{ public static void main (String args [ ] ) { Test ob1 = new Test (2); Test ob2; ob2=ob1.incByTen(); System.out.println("ob1.a:" + ob1.a ); System.out.println("ob2.a:" + ob2.a ); ob2=ob2.incByTen(); System.out.println("ob2.a after Second increase :" + ob2.a ); } } DESCRIPTION: In this program we create a class and set a method in that class. In the method we add 10 in the object as required from the statement. Then in the main function we create a object of that class and then invoke that method and print them using System.out.println(). Then for second increment we again invoke method that increments the object by 10. OUTPUT: Q# 62. Write a program that that use the concept of recursion and find the factorial of the numbers. class Factorial{ int fact (int n ) { int result; if (n==1) return 1; result = fact(n-1)*n; 54 | P a g e
  56. 56. JAVA & OOPS Manual return result; } } class Recursion{ public static void main (String args []) { Factorial f= new Factorial (); System.out.println("Factorial of 5 is " + f.fact(5)); System.out.println("Factorial of 7 is " + f.fact(7)); System.out.println("Factorial of 9 is " + f.fact(9)); } } DESCRIPTION: In this program we find the factorial of numbers. This is a recursive program in which we create a function of name fact(). When it will call with an argument of 1, the function returns 1, otherwise it will return the product of fact(n-1)*n . To evaluate this expression fact () is called with (n-1) .This process repeats until n =1. OUTPUT: Q# 63. Write a program that shows recursion. CODE: class Rectest{ int values[]; Rectest (int i){ values = new int[ i ]; } //display array-- recursively void printArray( int i){ if ( i == 0 ) return; else printArray(i - 1); System.out.println(" [" + (i-1) + "] " + values [ i -1 ] ); } 55 | P a g e
  57. 57. JAVA & OOPS Manual } class Recursion2{ public static void main(String args[]){ Rectest ob = new Rectest(10); int i; for(i=0 ; i<10 ; i++) ob.values[i] = i; ob.printArray(10); } } Description: In this program first make a class after and intiliaze value after this make a constructor with single value , after this make void print array method than make another class which is main class in this class declare new object ob than initialize I after this declare for loop than call printarray() function. OUTPUT: Q# 64. Write a program that shows the working of access specifies. Like we can access public methods and variables but not private one. class test{ int a; //default access public int b; //public access private int c; //private access void setc(int z){ c = z; } int getc(){ return c; } } 56 | P a g e
  58. 58. JAVA & OOPS Manual class AccessTest{ public static void main(String args[]){ test ob = new test(); ob.a =10; //correct ob.b = 20; // //ob.c = 100; ob.setc(100); //this is not Ok(Error) // System.out.println("The values of a , b and c are : " + ob.a+" " + ob.b +" "+ ob.getc() ); } } DESCRIPTION:In this program we simply shows the working of access specifier. This program shows that in java or any other language we can access public methods and public variables from outside the class but we can’t access a private method or private variable form outside the class. There is one type also called protected whose methods and variables can access only by the child classes but not from outside the class. OUTPUT: Q# 65. Write a program that uses variable , method and blocks class UseStatic { static int a=3; static int b; static void meth(int x) { System.out.println("x = " + x); System.out.println("a = " + a); System.out.println("b = " + b); } static { System.out.println("static block initialize. "); b = a*4; } public static void main(String args []) { 57 | P a g e
  59. 59. JAVA & OOPS Manual meth(42); } } Description: In this program first make a class than initialize static member a and b, after this make a method name as static void meth in this function print value of x , a, and b , after this write main method and call meth. Output: Q# 66. Write a program that inside main() the static method accessed outside of the class. Class StaticDemo { Static int a = 42; Static int b = 99; Static void callme( ) { System.out.println(―a = ―+ a); } } Class StaticByName { Public static void main (String args []) { StaticDemo.callme(); } } Description: in this program first make a class after this make a class as name StaticDemo after this initialize static data member, than print value of a , after this make a main class and print the value of b. Output: 58 | P a g e
  60. 60. JAVA & OOPS Manual Q# 67. Write a program that demonstrates an inner class with in for loop. class Outer { int outer_x = 100; void test () { for (int i = 0; i<10; i++ ); { // declare for loop class Inner { void display ( ) { System.out.println("display : outer_x = " + outer_x); // prit value outer_x } } Inner inner = new Inner(); inner . display( ); // display method call } } } class InnerClassDemo { public static void main (String args [ ]) { // main body of program start from here Outer outer = new Outer (); outer.test (); // declare objrct // call test method } } Description:In this program first make class outer and initialize outer_x after this make method test, and for loop declare after this make class inner than declare display method, and call with inner object , than make main class and make new object outer and call test method. Output: Q# 68. Write a program that demonstrates Strings. class StringDemo { //declare class public static void main (String args []) { 59 | P a g e // main body of program start
  61. 61. JAVA & OOPS Manual String strOb1 = "First String "; //Declare strOb1 String strOb2 = "Second String "; //Declare strOb2 String strOb3 = strOb1 + " and " + strOb2; System.out.println(" strOb1 "); // print strOb1 System.out.println(" strOb2 "); // print strOb2 System.out.println(" strOb3 "); //Declare strOb3 // print strOb3 } } Description: this is a simple program in which first declare object then print them. Output: Q# 69. Write a program that demonstrates some string method. class StringDemo2 { public static void main (String args []) { String strOb1 = "First String "; String strOb2 = "Second String "; String strOb3 = strOb1; System.out.println(" Length of strOb1 :" + strOb1.length()); System.out.println(" Char at index 3 in strOb1:" + strOb1.charAt(3)); if(strOb1.equals(strOb2)) System.out.println("strOb1 == strOb2 "); else System.out.println("strOb1 != strOb2"); if(strOb1.equals(strOb3)) System.out.print("strOb1 == strOb3 "); else System.out.println("strOb1 != strOb3"); } } 60 | P a g e
  62. 62. JAVA & OOPS Manual Description: Output: Q# 70. Write a program that display all command line arguments class CommandLine { // class name declare public static void main (String args [ ]) { //main body of program start from here for(int i=0; i<args.length; i++) // declare for loop System.out.println("args[ " + i + " ] :" + args[i]); // print arguments } } Description:in this program first make a class than main method of body start from here than for loop declare after this print value. Output: Q# 71. Write a program that uses inheritance to extend Box class Box{ double width; double height; double depth; //Construct Clone Of An Object Box(Box ob){ //Pass Object To Constructor width = ob.width; height = ob.height; depth = ob.depth; } Box(double w, double h, double d){//Constructor Used When All Dimensions Specified 61 | P a g e
  63. 63. JAVA & OOPS Manual width = w; height = h; depth = d; } Box(){//Constructor Used When No Dimensions Specified width = -1; height = -1; depth = -1; } Box(double len){//Constructor Used When Cube Is Created width = height = depth = len; } double volume(){ //Compute And Return Volume return width * height * depth; } } class BoxWeight extends Box{//Here, Box Is Extended To Include Weight. double weight; //Weight Of Box BoxWeight(double w, double h, double d, double m){ width = w; height = h; depth = d; weight = m; } } class DemoBoxWeight{ public static void main(String args[]){ BoxWeight mybox1 = new BoxWeight(10, 20, 15, 34.3); BoxWeight mybox2 = new BoxWeight(2, 3, 4, 0.076); double vol; vol = mybox1.volume(); System.out.println("Volume of mybox1 is " + vol); 62 | P a g e //Constructor For BoxWeight
  64. 64. JAVA & OOPS Manual System.out.println("Weight of mybox1 is " + mybox1.weight); System.out.println(); vol = mybox2.volume(); System.out.println("Volume of mybox2 is " + vol); System.out.println("Weight of mybox2 is " + mybox2.weight); } } Description: Output: Q# 72. Write a program that show Super keyword implementation of BoxWeight. class Box{ //class name private double width; //declare width private double height; //declare height private double depth; //declare depth Box(Box ob){ width = ob.width; // define constructor //give value to ob height = ob.height; depth = ob.depth; } Box(double w, double h, double d){ width = w; //declare w height = h; //declare h depth = d; } Box() { width = -1; height = -1; depth = -1; 63 | P a g e //declare d //define Box constructor
  65. 65. JAVA & OOPS Manual } Box(double len) { // again constructor define which define len width = height = depth = len; } double volume() { //volume funcation return width * height * depth; // return value of volume } } class BoxWeight extends Box { double weight; //BoxWeight inherited from Box //declare weight BoxWeight(BoxWeight ob) { super(ob); weight = ob.weight; //constructor define //call super to ob //initiliaze weight } BoxWeight(double w, double h, double d, double m) { with 3 arguments //define constructor super(w, h, d); weight = m; } BoxWeight() { super(); weight = -1; } BoxWeight(double len, double m) { super(len); weight = m; } } class DemoSuper { public static void main(String args[]) { BoxWeight mybox1 = new BoxWeight(10, 20, 15, 34.3); 64 | P a g e //initialize myBox1
  66. 66. JAVA & OOPS Manual BoxWeight mybox2 = new BoxWeight(2, 3, 4, 0.076); myBox2 //initialize BoxWeight mybox3 = new BoxWeight(); // by default BoxWeight mycube = new BoxWeight(3, 2); // initialize mycube BoxWeight myclone = new BoxWeight(mybox1); // declare my clone double vol; vol = mybox1.volume(); //declare vol System.out.println("Volume of mybox1 is " + vol); //print volume of myBox1 System.out.println("Weight of mybox1 is " + mybox1.weight); of myBox 1 // print weight System.out.println(); //print nothing vol = mybox2.volume(); //declare vol System.out.println("Volume of mybox2 is " + vol); //print volume of myBox2 System.out.println("Weight of mybox2 is " + mybox2.weight); of myBox System.out.println(); vol = mybox3.volume(); // print weight //print nothing // declare vol System.out.println("Volume of mybox3 is " + vol); //print volume of mybox3 System.out.println("Weight of mybox3 is " + mybox3.weight); of myBox3 // print weigh System.out.println(); vol = myclone.volume(); System.out.println("Volume of myclone is " + vol); System.out.println("Weight of myclone is " + myclone.weight); System.out.println(); vol = mycube.volume(); System.out.println("Volume of mycube is " + vol); System.out.println("Weight of mycube is " + mycube.weight); System.out.println(); } } Description: In this program first a class name Box in this class I define weight, height, and depth, after this make constructor with one argument ob and declare ob in it. After this make constructor with 65 | P a g e
  67. 67. JAVA & OOPS Manual three arguments than define bydefault constructor. After this volume method define. Than make another class which extends Box, in this class define new object weight , than make theor constructor in BoxWeight() method super method call, after this main class define , and define new object print their values which are define in above class . Output: Q# 73. cost. Write a program in which BoxWeight extends to includinf shipping class Box { // class na,e declare private double width; //declare width private double height; //declare height private double depth; //declare depth Box(Box ob) { // make constructor width = ob.width; // pass object to constructor height = ob.height; depth = ob.depth; } Box(double w, double h, double d) { dimensions specified // constructor used when all width = w; height = h; depth = d; } Box() { // constructor used when no dimensions specified width = -1; height = -1; depth = -1; } Box(double len) { width = height = depth = len; } 66 | P a g e // constructor used when cube is created
  68. 68. JAVA & OOPS Manual double volume() { // compute and return volume return width * height * depth; } } class BoxWeight extends Box { double weight; // weight of box BoxWeight(BoxWeight ob) { super(ob); // construct clone of an object // pass object to constructor weight = ob.weight; } BoxWeight(double w, double h, double d, double m) { parameters are specified super(w, h, d); // constructor when all // call superclass constructor weight = m; } BoxWeight() { // default constructor super(); weight = -1; } BoxWeight(double len, double m) { // constructor used when cube is created super(len); weight = m; } } class Shipment extends BoxWeight { // Add shipping costs. double cost; Shipment(Shipment ob) { super(ob); // construct clone of an object // pass object to constructor cost = ob.cost; } Shipment(double w, double h, double d, double m, double c) { when all parameters are specified 67 | P a g e // constructor
  69. 69. JAVA & OOPS Manual super(w, h, d, m); cost = c; // call superclass constructor } Shipment() { // default constructor super(); cost = -1; } Shipment(double len, double m, double c) {// constructor used when cube is created super(len, m); // call Super cost = c; //declare cost } } class DemoShipment { public static void main(String args[]) { Shipment shipment1 =new Shipment(10, 20, 15, 10, 3.41); Shipment shipment2 =new Shipment(2, 3, 4, 0.76, 1.28); double vol; vol = shipment1.volume(); //decare vol // initiliaze volume System.out.println("Volume of shipment1 is " + vol); System.out.println("Weight of shipment1 is "+ shipment1.weight); System.out.println("Shipping cost: $" + shipment1.cost); System.out.println(); vol = shipment2.volume(); //decare vol // initiliaze volume System.out.println("Volume of shipment2 is " + vol); System.out.println("Weight of shipment2 is "+ shipment2.weight); System.out.println("Shipping cost: $" + shipment2.cost); } } Description: In this program first a class name Box in this class I define weight, height, and depth, after this make constructor with one argument ob and declare ob in it. After this make constructor with three arguments than define bydefault constructor. After this volume method define. Than make 68 | P a g e
  70. 70. JAVA & OOPS Manual another class which extends Box, in this class define new object weight , than make another constructor in BoxWeight() method super method call,after this make class Shipment which extends Boxweightin this class cost shipment is defined in constructor of shipment class. after this main class define , and define new object print their values which are define in above class Output: Q# 74. Write a program that demonstrate when constructor are called. class A { //class name declare A() { System.out.println("Inside A's constructor."); } } class B extends A { // Create a subclass by extending class A. B() { System.out.println("Inside B's constructor."); } } class C extends B { // Create another subclass by extending B. C() { System.out.println("Inside C's constructor."); } } class CallingCons { // class name definition public static void main(String args[]) { // main body of program start C c = new C(); } } Description: In this program first define a class A and its constructor , after this make another class B which is inherited from A, make the constructor and print value , after this make another class c which is inherited from class B, than make main class and make new object cand print . Output: 69 | P a g e
  71. 71. JAVA & OOPS Manual Q# 75. Write a program that show method overriding. class A{ int i, j; A(int a, int b) { i = a; j = b; } void show() { // display i and j System.out.println("i and j: " + i + " " + j); } } class B extends A { int k; B(int a, int b, int c) { super(a, b); k = c; } void show() { // display k – this overrides show() in A System.out.println("k: " + k); } } class Override { public static void main(String args[]) { B subOb = new B(1, 2, 3); subOb.show(); } } Description: 70 | P a g e // this calls show() in B
  72. 72. JAVA & OOPS Manual Output: Q# 76. Write a program that use Dynamic method dispatch. class A { void callme() { System.out.println("Inside A's callme method"); } } class B extends A { void callme() { // override callme() System.out.println("Inside B's callme method"); } } class C extends A { void callme() { // override callme() System.out.println("Inside C's callme method"); } } class Dispatch { public static void main(String args[]) { A a = new A(); // object of type A B b = new B(); // object of type B C c = new C(); // object of type C A r; // obtain a reference of type A r = a; // r refers to an A object r.callme(); r = b; r.callme(); r = c; r.callme(); 71 | P a g e // calls A's version of callme // r refers to a B object // calls B's version of callme // r refers to a C object // calls C's version of callme
  73. 73. JAVA & OOPS Manual } } Description: Output; Q# 77. Write a program that use run time poly-morphisam. class Figure { double dim1; double dim2; Figure(double a, double b) { dim1 = a; dim2 = b; } double area() { System.out.println("Area for Figure is undefined."); return 0; } } class Rectangle extends Figure { Rectangle(double a, double b) { super(a, b); } double area() {// override area for rectangle System.out.println("Inside Area for Rectangle."); return dim1 * dim2; } } class Triangle extends Figure { Triangle(double a, double b) { super(a, b); } double area() { // override area for right triangle System.out.println("Inside Area for Triangle."); return dim1 * dim2 / 2; } } class FindAreas { public static void main(String args[]) { Figure f = new Figure(10, 10); 72 | P a g e
  74. 74. JAVA & OOPS Manual Rectangle r = new Rectangle(9, 5); Triangle t = new Triangle(10, 8); Figure figref; figref = r; System.out.println("Area is " + figref.area()); figref = t; System.out.println("Area is " + figref.area()); figref = f; System.out.println("Area is " + figref.area()); } } Description: Through the dual mechanisms of inheritance and run-time polymorphism, it is possible to define one consistent interface that is used by several different, yet related, types of objects. In this case, if an object is derived from Figure, then its area can be obtained by calling area( ). Output: Q# 78. Write a program that use abstract method and classe. abstract class Figure { double dim1; double dim2; Figure(double a, double b) { dim1 = a; dim2 = b; } // area is now an abstract method abstract double area(); } class Rectangle extends Figure { Rectangle(double a, double b) { super(a, b); } // override area for rectangle double area() { 73 | P a g e
  75. 75. JAVA & OOPS Manual System.out.println("Inside Area for Rectangle."); return dim1 * dim2; } } class Triangle extends Figure { Triangle(double a, double b) { super(a, b); } // override area for right triangle double area() { System.out.println("Inside Area for Triangle."); return dim1 * dim2 / 2; } } class AbstractAreas { public static void main(String args[]) { // Figure f = new Figure(10, 10); // illegal now Rectangle r = new Rectangle(9, 5); Triangle t = new Triangle(10, 8); Figure figref; // this is OK, no object is created figref = r; System.out.println("Area is " + figref.area()); System.out.println("Area is " + figref.area()); } } Description: As the comment inside main( ) indicates, it is no longer possible to declare objects of type Figure, since it is now abstract. And, all subclasses of Figure must override area( ). To prove this to yourself, try creating a subclass that does not override area( ). You will receive a compile-time error Output: 74 | P a g e
  76. 76. JAVA & OOPS Manual Chapter # 10(Exception Handling) Q# 79. Write a program using exceptions in it class Exc2{ public static void main(String args[]){ int d,a; try{ d=0; a=42/d; System.out.println("This will not be printed"); } catch(ArithmeticException e){ System.out.println("Division by zero"); } System.out.println("After catch statement"); } } Description: Notice that the call to println( ) inside the try block is never executed. Once an exception is thrown, program control transfers out of the try block into the catch block. Put differently, catch is not ―called,‖ so execution never ―returns‖ to the try block from a catch. Thus, the line ―This will not be printed.‖ is not displayed. Once the catch statement has executed, program control continues with the next line in the program following the entire try/catch mechanism. Output: Q# 80. Write a program showing multiple catch Clauses. class Multicatch{ public static void main(String args[]){ try{ int a=args.length; System.out.println("a="+a); int b=42/a; int c[]={1}; c[42]=99; } catch(ArithmeticException e){ System.out.println("Divide by 0:"+e); } catch(ArrayIndexOutOfBoundsException e){ System.out.println("Array index oob: "+e); 75 | P a g e
  77. 77. JAVA & OOPS Manual } System.out.println("After try/catch blocks."); } } Description: This program will cause a division-by-zero exception if it is started with no command line arguments, since a will equal zero. It will survive the division if you provide a command line argument, setting a to something larger than zero. But it will cause an. ArrayIndexOutOfBoundsException, since the int array c has a length of 1, yet the program attempts to assign a value to c[42]. Output: Q# 81. Write a program that Handle an exception and move on. import java.util.Random; class HandleError { public static void main(String args[]) { int a=0, b=0, c=0; Random r = new Random(); for(int i=0; i<32000; i++) { try { b = r.nextInt(); c = r.nextInt(); a = 12345 / (b/c); } catch (ArithmeticException e) { System.out.println("Division by zero."); a = 0; // set a to zero and continue } System.out.println("a: " + a); } } } Output: 76 | P a g e
  78. 78. JAVA & OOPS Manual Q# 82. write a program of try statements class NestTry { public static void main(String args[]) { try { int a = args.length; //If no command-line args are present, the following statement will generate a divide-by-zero exception int b = 42 / a; System.out.println("a = " + a); try { // nested try block //If one command-line arg is used, then a divide-by-zero exception will be generated by the following code if(a==1) a = a/(a-a); // division by zero //If two command-line args are used, then generate an out-of-bounds exception if(a==2) { int c[] = { 1 }; c[42] = 99; // generate an out-of-bounds exception 77 | P a g e
  79. 79. JAVA & OOPS Manual } } catch(ArrayIndexOutOfBoundsException e) { System.out.println("Array index out-of-bounds: " + e); } } catch(ArithmeticException e) { System.out.println("Divide by 0: " + e); } } } Description: As you can see, this program nests one try block within another. The program works as follows. When you execute the program with no command-line arguments, a divide-by-zero exception is generated by the outer try block. Execution of the program with one command-line argument generates a divide-by-zero exception from within the nested try block. Since the inner block does not catch this exception, it is passed on to the outer try block, where it is handled. If you execute the program with two command-line arguments, an array boundary exception is generated from within the inner try block. Here are sample runs that illustrate each case. Output: Q# 83. Write a program that can be implicitly nested via calls to methods. */ class MethNestTry { static void nesttry(int a) { try { // nested try block //If one command-line arg is used, then a divide-by-zero exception will be generated by the following code if(a==1) a = a/(a-a); // division by zero //If two command-line args are used, then generate an out-of-bounds exception if(a==2) { int c[] = { 1 }; c[42] = 99; } } 78 | P a g e // generate an out-of-bounds exception
  80. 80. JAVA & OOPS Manual catch(ArrayIndexOutOfBoundsException e) { System.out.println("Array index out-of-bounds: " + e); } } public static void main(String args[]) { try { int a = args.length; //If no command-line args are present, the following statement will generate a divide-by-zero exception int b = 42 / a; System.out.println("a = " + a); nesttry(a); } catch(ArithmeticException e) { System.out.println("Divide by 0: " + e); } } } Description: As you can see, this program nests one try block within another. The program works as follows. When you execute the program with no command-line arguments, a divide-by-zero exception is generated by the outer try block. Execution of the program with one command-line argument generates a divide-by-zero exception from within the nested try block. Since the inner block does not catch this exception, it is passed on to the outer try block, where it is handled. If you execute the program with two command-line arguments, an array boundary exception is generated from within the inner Output: Chapter#13 (String Handling) Q# 84. Write a program that use override toString () for Box. class Box { double width; double height; double depth; 79 | P a g e
  81. 81. JAVA & OOPS Manual Box(double w, double h, double d) { width = w; height = h; depth = d; } public String toString () { return "Dimension are " + width + " By " + depth + " By " + height + " . "; } } class toStringDemo { public static void main (String args []) { Box b = new Box (10, 12, 14) ; String s =( "Box b :" + b); //Concatinate box object System.out.println(b); //Convert Box to String System.out.println(s); //print value of s. } //ending brace of main program } //ending brace of class Description: In this program first make a class than write its main body after this declares s and print value of b and s. Output: Q# 85. Write a program that demonstrate equals () and equalsIgnoreCase(). //Demonstrate equals() and equalIgnoreCase(). public class EqualsDemo { public static void main (String[] args) { String s1 = "Hellow"; // Declare and initialize s1 String s2 = "Hellow"; // Declare and initialize s2 String s3 = "Good-By"; // Declare and initialize s3 String s4 = "HELLOW"; // Declare and initialize s4 80 | P a g e
  82. 82. JAVA & OOPS Manual System.out.println(s1 + " equals " + s2 + "->" + s1.equals(s2)); System.out.println(s1 + " equals " + s3 + "->" + s1.equals(s3)); System.out.println(s1 + " equals " + s4 + "->" + s1.equals(s4)); System.out.println(s1 + " equals " + s2 + "->" + s1.equalsIgnoreCase(s2)); } } Description: In this program first make class than write its main method after this initialize String s1 to s4 than print values by equals method. Output: Q# 86. Write a program that use == method to give answer. public class EqualsNotEqualsTo { public static void main (String[] args) { String s1 = "Helow"; String s2 = new String (s1); System.out.println(s1 + " equals " + s2 + "->" + s1.equals(s2)); System.out.println(s1 + "==" + s2 + "->" + (s1==s2)); } } Description: Output: Q# 87. Write a program that use compareTo() to determine sort ordering for a bubble sort. //A bubble sort for string public class SortString { static String arr[] = { 81 | P a g e
  83. 83. JAVA & OOPS Manual "my","Name","is","khan","i","am","the","student","of","BSCS.","i","am","studing","in"," NFC","IEFR","Faisalabad" }; public static void main (String[] args) { for(int j = 0; j <arr.length; j++){ for(int i =j+1; i<arr.length;i++){ if(arr[i].compareTo(arr[j])< 0){ String t = arr[j]; arr[j] = arr[i]; arr[i] = t; } } System.out.println(arr[j]); } } } Description: Output: Q# 88. Write a program that show how to use various index method t search inside of string. public class IndexOfDemo { public static void main(String[] args) { String s = " my name is hussain ahmad khan , i am the student of BSCS " + "gradugate doing from Nfc IEFR Faisalabad Punjab Pakistan."; System.out.println(s); System.out.println("Last Index of (t) = " + s.indexOf('t')); System.out.println("Last Index of (t) = " + s.lastIndexOf('t')); 82 | P a g e
  84. 84. JAVA & OOPS Manual System.out.println("Last Index of (the) = " + s.indexOf("the")); System.out.println("Last Index of (the) = " + s.lastIndexOf("the")); System.out.println("Last Index of (t,10) = " + s.indexOf('t',10)); System.out.println("Last Index of (t, 60) = " + s.lastIndexOf('t', 60)); System.out.println("Last Index of (the,10) = " + s.indexOf("the",10)); System.out.println("Last Index of (the, 60) = " + s.lastIndexOf("the", 60)); } } Description: Output: Q# 89. Write a program that use substring() method to replace all instance of one substring with another within string. class StringReplace { public static void main (String[] args) { String org = "This is a Test. This is , too."; String search = "is"; String sub = "was"; String result = " "; int i; do { //replase all matching substring System.out.println(org); i = org.indexOf(search); if(i != -1){ result = org.substring(0, i); result = result + sub ; result = result + org.substring(i + search.length()); org = result; } 83 | P a g e
  85. 85. JAVA & OOPS Manual } while (i != -1); } } Description: Output: Q# 90. Write a program that use trim() to process commands. import java.io.*; //this is for taking input and output public class UseTrim { //class name declare public static void main(String[] args) throws IOException { // main body of programme // BufferedReader br = new BufferedReader (new InputStreamReader(System.in)) ;// creat bufferedReader using System.in String str; //declare str System.out.println("Enter 'Stop' to quite. "); System.out.println("Enter State: "); do { //print line // do while declare str = br.readLine(); str = str.trim(); // print the line //Call readLine() method to str //remove whitespace if (str.equals("Illionois")) //define if statement System.out.println("Capital spring feild."); else if (str.equals("Missouri")) //print the line //else statement difine System.out.println("Capital is Jefferson city"); // print capital is Jefferson city else if(str.equals("California")) statement // otherwise equals method call using if System.out.println("Capital is Scramemento"); else if (str.equals("Washhington")) statement // print value //again equls method call using else if System.out.println("Capital is Olampia."); // print capital is olampia. 84 | P a g e
  86. 86. JAVA & OOPS Manual } while(!str.equals("stop")); //while condition define } } Description: First declare class name Output: Q# 91. Write a program that convert uppercase latter to lowercase and lowercase to uppercase latters. public class ChangeCase { //class name declare public static void main(String[] args) { String s = "This is a test."; //main body of program start from here //declare and initialize s System.out.println("Orignal sentence:" + s); // print value of s String upper = s.toUpperCase(); //call toUpperCase() method String lower = s.toLowerCase (); //call toLowerCase() method System.out.println("Upper: " + upper); // print string line in upper case System.out.println("Lower case: " + lower); } // print string line in lower case // ending brace of main body } //ending brace of class Description: In this code first make a class than start main body of program. Than declare s and then call toLoweCase() method and toUpperCase() method. Than print their their value. Output: Q# 92. Write a program that define StringBuffer length vs. capacity. class StringBufferDemo { public static void main (String[] args) { 85 | P a g e

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