Program on Decimal to Octal Number Conversion

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

Note: Octal Number system is a number system which can represent a number in any other number system in terms of digits ranging from 0 to 7 only. This number system consists of only eight basic digits i.e. 0, 1, 2, 3, 4, 5, 6 and 7.

For Example: 25 in the Decimal number system can be represented as 31 in the Octal number system.

import java.io.*;

class Dec2Oct

{

    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

 

        //array storing the digits (as characters) in the octal number system

        char dig[]={'0','1','2','3','4','5','6','7'};

 

        while(n>0)

            {

                r=n%8; //finding remainder by dividing the number by 8

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

                n=n/8;

            }

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

    }

}




Output:

Enter a decimal number : 25
Output = 31

Enter a decimal number : 465
Output = 721