Why my while loops doesn't recognize the condition of the integer and make infinite loop? (Java while loops "Validate a bank Pin")

Question

I have tried inputing the same int as the validPin variable, but it makes infinite loop even though the condition is already true. Also, I have tried to change validPin to 12345 and it worked, but if the validPin is 002200 it doesnt work. Why?

public void main() {

    Scanner in = new Scanner(System.in);
    int validPin = 002200;
    System.out.print("Enter PIN to access:");
    int pin = in.nextInt();


    while (pin != validPin) {
        System.out.print("Invalid PIN, Try again:");
        pin = in.nextInt();
    }

    System.out.println("You have entered the correct PIN, now you have acces for your account!");

}

}

`002200` is `2200` for an int, did you try it? Maybe you should use strings instead primitive integers — SerCrAsH, Apr 14 '21 at 22:53

score 3 · Answer 1 · answered Apr 14 '21 at 22:54

In Java source code, 002200 is the decimal value 1152, and for nextInt, 002200 is the decimal value 2200.

(This is an annoying throwback from C that should never have been adopted in Java, but we're stuck with it).

Read about octal constants in Java source code - any tutorial should have this information.

Also, if you require the user to actually type those leading zeroes, you may be better off using strings rather than ints.

Why my while loops doesn't recognize the condition of the integer and make infinite loop? (Java while loops "Validate a bank Pin")

1 Answers1