Here we are going to write a program to check given number is octal number or not using Java.

Check Octal Number or Not ?

import java.util.Scanner;

public class IsOctal_Check {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner sc = new Scanner(System.in);
        System.out.println("Enter Number : \n");
        String input = sc.nextLine();
        System.out.println("isOctal : "+isOctal(input));
    }
    
    public static boolean isOctal(String octal) {

        boolean isOctal = false;

        if (octal != null && !octal.isEmpty()) {
            int number = Integer.parseInt(octal);

            while (number > 0) {
                if (number % 10 <= 7) {
                    isOctal = true;
                } else {
                    isOctal = false;
                    break;
                }
                number /= 10;
            }
        }
        return isOctal;
    }
}

Output :

Enter Number :  20
isOctal : true
Enter Number :  18
isOctal : false

Happy Learning 🙂