Java Program for Binary, Decimal, Octal and HEX conversions

import java.util.*;

class Convert

{

public void binary(int n)

{

int s=0,pos=0;

while(n>0)

{

int dg=n%2;

s=s+dg*(int)Math.pow(10,pos++);

n=n/2;

}

System.out.println(s);

}

public void octal(int n)

{

int s=0,pos=0;

while(n>0)

{

int dg=n%8;

s=s+dg*(int)Math.pow(10,pos++);

n=n/8;

}

System.out.println(s);

}

public void hexadecimal(int n)

{

String s="";

int pos=0;

while(n>0)

{

int dg=n%16;

if(dg>9)

dg=dg+55;

else

dg=dg+48;

s=(char)dg+s;

n=n/16;

}

System.out.println(s);

}

public void binaryNO(int n)

{

int pos=0,s=0;

while(n>0)

{

int dg=n%10;

s=s+dg*(int)Math.pow(2,pos++);

n=n/10;

}

System.out.println(s);

}

public void octalNO(int n)

{

int pos=0,s=0;

while(n>0)

{

int dg=n%10;

s=s+dg*(int)Math.pow(8,pos++);

n=n/10;

}

System.out.println(s);

}

public void hexadecimalNO(String s)

{

String digits = "0123456789ABCDEF";

s = s.toUpperCase();

int val = 0,pos=0;

for (int i = 0; i < s.length(); i++)

{

char c = s.charAt(i);

int d = digits.indexOf(c);

val =16*val + d;

}

System.out.println( val);

}

}

public class Convertmain

{

public static void main(String args[])

{

Convert ob=new Convert();

Scanner sc=new Scanner(System.in);

System.out.println("Enter your choice : - \n1 for Decimal to Binary \n2 for Decimal to Octal \n3 for Decimal to Hexadecimal \n4 for Binary to Decimal \n5 for Octal to Decimal \n6 for Hexadecimal to Decimal");

int ch=sc.nextInt();

String s="";

int n=0;

System.out.println("\nEnter your value");

if(ch==6)

s=sc.next();

else

n=sc.nextInt();

System.out.println("\nYour result is");

switch(ch)

{

case 1:ob.binary(n);

break;

case 2:ob.octal(n);

break;

case 3:ob.hexadecimal(n);

break;

case 4:ob.binaryNO(n);

break;

case 5:ob.octalNO(n);

break;

case 6:ob.hexadecimalNO(s);

break;

default:System.out.println("Wrong input");

}

}

}