Java Exercises: Convert a decimal number to octal number

Java Basic: Exercise-21 with Solution

Write a Java program to convert a decimal number to octal number.

Decimal number: The decimal numeral system is the standard system for denoting integer and non-integer numbers. It is also called base-ten positional numeral system.

Octal number: The octal numeral system is the base-8 number system, and uses the digits 0 to 7.

Pictorial Presentation: Decimal to Octal number

Sample Solution:

Java Code:

import java.util.Scanner;
public class Exercise21 {
      public static void main(String args[])
    {
            int dec_num, rem, quot, i=1, j;
        int oct_num[] = new int[100];
        Scanner scan = new Scanner(System.in);
		
        System.out.print("Input a Decimal Number: ");
        dec_num = scan.nextInt();
		
        quot = dec_num;
		
        while(quot != 0)
        {
            oct_num[i++] = quot%8;
            quot = quot/8;
        }
		
        System.out.print("Octal number is: ");
        for(j=i-1; j>0; j--)
        {
            System.out.print(oct_num[j]);
        }
		System.out.print("\n");
    }
}

Sample Output:

Input a Decimal Number: 15                                                                                    
Octal number is: 17

Flowchart:

Java Code Editor:

Contribute your code and comments through Disqus.

Previous: Write a Java program to convert a decimal number to hexadecimal number.
Next: Write a Java program to convert a binary number to decimal number.