Java Program to Convert Octal Number to Decimal Number

In this tutorial, we will write a program to convert octal to decimal in java. Before that, you must have knowledge of the following topics in C++.

Octal number

The octal numbers are the numbers with base 8 and use the digits 0 to 7. Example: 8 in decimal is represented as 10 in octal, 25 as 31, and so on.

Decimal Number

These are the numbers with a base of 10, which ranges from 0 to 9. These numbers are formed with the combination of 0 to 9 digits such as 24, 345, etc.

Conversion example:

Input: 23
Output: 19

Let us go through a program for the octal to decimal Conversion in java.


Java Program to Convert Octal to Decimal using while loop

import java.util.Scanner;

public class Main
{
  public static void main(String[] args)
  {
    int octalNum, decimalNumber = 0, i = 0;
    Scanner scan = new Scanner(System.in);

    System.out.print("Enter an Octal Number: ");
    octalNum = scan.nextInt();

    while (octalNum != 0)
    {
      decimalNumber += (octalNum % 10) *Math.pow(8, i);
      ++i;
      octalNum /= 10;
    }

    System.out.printf("Equivalent Decimal Number: %d", decimalNumber);
  }
}

Output:

Enter an Octal Number: 23
Equivalent Decimal Number: 19