The document provides an overview of core Java concepts including try-catch blocks, reading input from the keyboard, control flow statements like if-else and switch, looping with for, while, and do-while loops, arrays, inheritance, overriding, abstract classes, interfaces, and packages. It includes code examples and discusses concepts like exception handling, control flow, looping, arrays, object-oriented programming principles of inheritance and polymorphism.

1. Core Java
Presenting overview of core java
Presented by
Uday Sharma 1

2. Agenda
• Try-Catch
• Read Input from Keyboard
• Control Flow
• Looping
• Array
• Exercises
• Inheritance
• Overriding
• Abstract
• Interface
• Packages
• Project work
2

3. Try-catch block
Try – catch block is useful to try statement or syntax if
there is any error catch block will handle exception
Syntax Exception
try int a=10;
{ int b=0;
int c;
// Body--------------
try{
} c = a/b;
catch(Exception e) }
{ catch(Exception e)
// Body------------ {
System.out.println(e);
}
}
3

4. Read Integer Input
From Keyboard
try
{
int a;
BufferedReader br = new BufferedReader(new
InputStreamReader(System.in));
System.out.println("Enter value of a= ");
a = Integer.parseInt(br.readLine());
//float y = Float.parseFloat(stdin.readLine());-- For float
}
catch(Exception e){}
4

5. Read String Input
From Keyboard
try{
while( (strLine = br.readLine()) != null)
{ if(strLine.equals("exit"))
break;
System.out.println("Line entered : " + strLine);
}
br.close();
}
catch(Exception e)
{
System.out.println("Error while reading line from console : " + e);
}
5

6. Control flow statement
• IF- ELSE boolean blnStatus = true;
Syntax
if() { if(blnStatus==true) {
body; System.out.println("Status is true");
} }
else {
else {
System.out.println("Status is false");
body; }
}
6

7. Nested if else
• IF- ELSE int printOption =1;
Syntax int scanOption =2;
int copyOption =3;
if() { int value = 1;
body; if(value==1) {
} System.out.println(“Priting…..");
}
else if() { else if(value==2){
body; System.out.println(“Scanning…..");
}
} else if(value==3){
else { System.out.println(“copyOption");
}
body; else {
} System.out.println(“Machine either in
idle stage or switch off");
} 7

8. For Loop
Syntax
for( <initialization> ; <condition> ; <statement> ){
<Block of statements>;
}
Example
for(int i=0 ; i < 5 ; i++)
{
System.out.println(“i is : “ + i);
}
8

9. For loop example
• Build pyramid
*
**
***
****
*****
• Build pyramid 2
*****
****
***
**
*
9

10. Group work
• Pyramid 3 • Numeric pyramid
* 1
** 12
*** 123
**** 1234
***** 12345
*****
****
***
**
*
10

11. While loop
syntax
while(<boolean condition>){
<Block of statements>;
}
Example
while(i < 5)
{
System.out.println("i is : " + i);
i++;
}
11

12. Do while loop
Syntax
Do{
<Block of statements>;
}while(<boolean condition>);
Example
do
{
System.out.println("i is : " + i);
i++;
}while(i < 5);
12

13. Switch Statement
Syntax
The switch statement is Java’s
switch (expression)
multiway branch statement. It
{ provides an easy way to dispatch
case value 1 : execution to different parts of
statement 1 ; break; your code based on the value of
... an expression.
case value N :
statement N ; break;
default :
statements ; break;
}
13

14. Array in Java
Syntax
dataType[] arrayRefVar = new dataType[arraySize];
dataType[] arrayRefVar = {value0, value1, ..., valuek};
Example
Double[] myList = new double[10];
14

15. Design car
• Design car parts 4 tyre (1- 2 front tyre and 3-4 back
tyre), 4 doors (1- 2 front doors and 3-4 back doors), 4
headlight (2 front light and 2 break light), 1 body, 2
Glass (front and rear glass), 1 Mirror, 4 seat (2 front
seat (Left is driver seat), and 2 back seat) .
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16. Java Exampe
Make saperate class for below mentioned all functionality
and attach all classes using interitance.
Note : Make super class Area with 2 memeber variable and
extend it another classes.
Triangle
Square
Area = ½ × b × h
Area = a2
b = base
a = length of side
h = vertical height
Rectangle Parallelogram
Area = w × h Area = b × h
w = width b = base
h = height h = vertical height
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17. Java Overriding
• The benefit of overriding is: ability to define a
behavior that's specific to the sub class type. Which
means a subclass can implement a parent calss
method based on its requirement.
• In object oriented terms, overriding means to
override the functionality of any existing method.
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18. Animal Example
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19. Class Name: Animal
hasEye
+Leg()
+Run()
+Jump()
+eye()
+Body()
19

20. Class Name: Girrafe
hasLeg
hasTail
hasColor
hasHeight
+Leg(hasLeg)
+Run()
+eye()
+Tail(hasTail)
+Body(hasColor,hasHeight)
20