Basic Java programs

1. Object Oriented Programming through Java
Assignment I
Submitted by: Anjali Soorej
IMCA-133
1. How to find if a number is power of 2 in Java?
PROGRAM
import java.util.Scanner;
public class Powerof2 {
public static void main(String[] args) {
int f=0;
System.out.print("Enter a number:");
Scanner input=new Scanner(System.in);
int num=input.nextInt();
if(num%2==0)
f=0;
else
f=1;
if(num==0)
f=1;
if(f==0)
System.out.println(num + "is a power of two");
else
System.out.println(num + "is not a power of two");
}
}

2. OUTPUT

3. 2. Write program to sort an integer array without using API methods?
PROGRAM
import java.util.Scanner;
public class Bubblesort {
public static void main(String[] args) {
int i,j,n,temp;
Scanner input=new Scanner(System.in);
System.out.print("Enter the limit of array:");
n=input.nextInt();
System.out.print("Enter the array elements:");
int a[]=new int[n];
for(i=0;i<n;i++)
a[i]=input.nextInt();
System.out.print("before sort:");
for(i=0;i<n;i++)
System.out.print(a[i] + " ");
for(i=0;i<n-i;i++)
for(j=0;j<n-i-1;j++)
{
if(a[j]>a[j+1])
{
temp=a[j];
a[j]=a[j+1];
a[j+1]=temp;
}
}
System.out.print("nafter sort:");
for(i=0;i<n;i++)
System.out.print(a[i] + " ");
}
}

4. OUTPUT

5. 3. Write Java program to check if a number is Armstrong number or not?
PROGRAM
import java.util.Scanner;
public class Amstrong {
public static void main(String[] args) {
int num,d,sum=0;
Scanner input=new Scanner(System.in);
System.out.print("Enter a number:");
num=input.nextInt();
int n=num;
while(n>0)
{
d=n%10;
sum=sum+(d*d*d);
n=n/10;
}
if(num==sum)
System.out.println(num+" is an amstrong number");
else
System.out.println(num + " is not an amstrong number");
}
}

6. OUTPUT

7. 4. Write a program in Java to reverse any String without using StringBuffer?
PROGRAM
import java.util.Scanner;
public class reverse {
public static void main(String[] args) {
char[] t=new char[100];
int i;
Scanner input=new Scanner(System.in);
System.out.print("Enter a string:");
String str=input.next();
char[] s=str.toCharArray();
int n=s.length;
for(i=0;i<n/2;i++)
{
t[i]=s[i];
s[i]=s[n-i-1];
s[n-i-1]=t[i];
}
System.out.print("reverse string:");
for(i=0;i<n;i++)
System.out.print(s[i]);
}
}

8. OUTPUT

9. 5. Write a program in Java to print Fibonacci series up to given number? Write both
iterative and recursive version.
PROGRAM
public class fibonacci {
int f=0,s=1,t;
void ifibonacci(int n)
{
System.out.print("iterative fibonacci series:");
if(n==0)
System.out.print(f);
System.out.print(f+" ");
for(int i=1;i<=n;i++)
{
f=s;
s=t;
t=f+s;
System.out.print(t+" ");
}
}
int rfibonacci(int n)
{
if ( n == 0 )
return 0;
else if ( n == 1 )
return 1;
else
return rfibonacci(n-1)+rfibonacci(n-2);
}
}
import java.util.Scanner;
public class Fib {
public static void main(String[] args) {
int n,c=0;
Scanner input=new Scanner(System.in);
System.out.print("enter a number:");
n=input.nextInt();
fibonacci f1=new fibonacci();
f1.ifibonacci(n);
System.out.print("nrecursive fibonacci series:");
for(int i=0;i<=n;i++)
{
System.out.print(f1.rfibonacci(c)+" ");
c++;
}
}
}

10. OUTPUT

11. 6. Write a Java program to calculate factorial of an integer number? Both iterative and
recursive solution.
PROGRAM
public class Factorial {
int i,f=1;
void ifactorial(int n)
{
for(i=n;i>=1;i--)
f=f*i;
System.out.println("iterative factorial:" + f);
}
int rfactorial(int n)
{
if(n>=1)
return n*rfactorial(n-1);
else
return 1;
}
}
import java.util.Scanner;
public class Fact {
public static void main(String[] args) {
Scanner input=new Scanner(System.in);
System.out.print("Enter a number:");
int n=input.nextInt();
Factorial f1=new Factorial();
f1.ifactorial(n);
int ans=f1.rfactorial(n);
System.out.println("recursive factorial:" + ans);
}
}

12. OUTPUT

13. 7. Print following structure in Java?
*
**
***
****
***
**
*
PROGRAM
public class Pattern {
public static void main(String[] args) {
int i,j;
for(i=1;i<=5;i++)
{
for(j=1;j<=i;j++)
System.out.print("*");
System.out.print("n");
}
for(i=4;i>=1;i--)
{
for(j=1;j<=i;j++)
System.out.print("*");
System.out.print("n");
}
}
}

14. OUTPUT

15. 8. Write a program to find factorial of list of number reading input as command line
argument.
PROGRAM
public class command {
public static void main(String args[]) {
int number;
int fact = 1;
int argsLength = args.length;
if(argsLength==1) {
number = Integer.parseInt(args[0]);
for(int count=1;count<=number;count++) {
fact = fact*count;
}
System.out.println("Factorial of "+number+" is: "+fact);
}
else if(argsLength>1)
System.out.println("More than one number is entered...");
else
System.out.println("No arguments entered...");
}
}

16. OUTPUT

17. 9. Write a program to display all prime numbers between two limits.
PROGRAM
import java.util.Scanner;
public class Primelimit {
public static void main(String[] args) {
int l,h,j,i,f;
Scanner input=new Scanner(System.in);
System.out.print("enter the lower limit:");
l=input.nextInt();
System.out.print("nenter the higher limit:");
h=input.nextInt();
System.out.println("prime numbers between "+l+" and "+h+" are:");
while(l<=h)
{
f=0;
for(j=2;j<=l/2;j++)
{
if(l%j==0)
{
f=1;
break;
}
}
if(l==1)
f=1;
if(f==0)
System.out.print(l +" ");
l++;
}
}
}

18. OUTPUT

19. 10. Write Java program to check if a number is palindrome in Java?
PROGRAM
import java.util.Scanner;
public class Palindrome {
public static void main(String[] args) {
int num,d,sum=0;
Scanner input=new Scanner(System.in);
System.out.print("Enter a number:");
num=input.nextInt();
int n=num;
while(n>0)
{
d=n%10;
sum=d+(sum*10);
n=n/10;
}
if(num==sum)
System.out.println(num+" is a palindrome number");
else
System.out.println(num + " is not a palindrome
number");
}
}

20. OUTPUT