Program on Decimal to Binary Number Conversion

Write a Program in Java to input a number in Decimal number system and convert it into its equivalent number in the Binary number system.

Note: Binary Number system is a number system which can represent a number in any other number system in terms of 0 and 1 only. This number system consists of only two basic digits i.e. 0 and 1.

For Example: 25 in the Decimal number system can be represented as 11001 in the Binary number system.

import java.io.*;

class Dec2Bin

{

    public static void main(String args[])throws IOException

    {

        BufferedReader br=new BufferedReader (new InputStreamReader(System.in));

        System.out.print("Enter a decimal number : ");

        int n=Integer.parseInt(br.readLine());

 

        int r;

        String s=""; //variable for storing the result

 

        char dig[]={'0','1'}; //array storing the digits (as characters) in a binary number system

 

        while(n>0)

            {

                r=n%2; //finding remainder by dividing the number by 2

                s=dig[r]+s; //adding the remainder to the result and reversing at the same time

                n=n/2;

            }

        System.out.println("Output = "+s);

    }

}




Output:

Enter a decimal number : 25
Output = 11001

Enter a decimal number : 47
Output = 101111

Enter a decimal number : 6
Output = 110