Java Program to Convert Decimal to Octal

This post covers a program in Java that converts a decimal number entered by user at run-time of the program, to its equivalent octal value.

Note - If you're not aware about, how the decimal to octal conversion takes place, then refer to Decimal to Octal Conversion.

Decimal to Octal Conversion in Java

The question is, write a Java program to convert decimal number to octal. The decimal number must be received by user at run-time. The program given below is its answer:

import java.util.Scanner;

public class CodesCracker
{
   public static void main(String[] args)
   { 
      int decimal, rem, i=0;
      int[] octal = new int[20];
      
      Scanner scan = new Scanner(System.in);
      
      System.out.print("Enter the Decimal Number: ");
      decimal = scan.nextInt();
      
      while(decimal != 0)
      {
         rem = decimal%8;
         octal[i] = rem;
         i++;
         decimal = decimal/8;
      }
      
      System.out.print("\nEquivalent Octal Value = ");
      for(i=(i-1); i>=0; i--)
         System.out.print(octal[i]);
   }
}

The sample run of above program with user input 439 as decimal number to convert and prints its equivalent octal value, is shown in the snapshot given below:

In above program, the following block of code:

rem = decimal%8;
octal[i] = rem;
i++;
decimal = decimal/8;

can also be replaced with the block of code, given below:

octal[i++] = decimal%8;
decimal /= 8;

Same Program in Other Languages

• C Decimal to Octal Conversion
• C++ Decimal to Octal Conversion
• Python Decimal to Octal Conversion

Java Online Test