Question

import java.util.Scanner;

public class asg3 {

    public static int setoriginal() {
        int d=0; 
        int l=0;                                                           
        do {   
            Scanner input = new Scanner(System.in);
            System.out.println("Please enter a 4 digit number: ");
            d=input.nextInt();
            if (d<=9999 || d>999) {
                break;
            } else {
                System.err.printf ("You did not enter 4 digits\n");
            }           
            l=l+1;
        } while (l<3);    
        return d;
    }

    public static void main(String[] args) {
        setoriginal();
    }
}

when I enter 12345 it works but doesn’t seem to work for any other number other than four-digit ones.
any idea of what could be wrong or what I am doing wrong?

Answer 1

Look at this condition:

if (d <= 9999 || d > 999)

For that to evaluate to false, you would have to find a value which is greater than 9999 and less than 1000. I think you’ll be hard pushed to find such a number…

I suspect you meant:

if (d <= 9999 && d > 999)

Personally I’d write this as:

if (d >= 1000 && d <= 9999)

or

if (1000 <= d && d <= 9999)

In all these versions, you’re basically checking that it’s greater than or equal to 1000 and it’s less than or equal to 9999.