Problem 48

Enter Your PIN

Type in the following code, and get it to compile. This assignment will help you learn how to make a loop, so that you can repeat a section of code over and over again!

import java.util.Scanner;

public class EnterPIN {
    public static void main(String[] args) {
        Scanner keyboard = new Scanner(System.in);
        int pin = 12345;

        System.out.println("WELCOME TO THE BANK OF MITCHELL.");
        System.out.print("ENTER YOUR PIN: ");
        int entry = keyboard.nextInt();

        while (entry != pin) {
            System.out.println("\nINCORRECT PIN. TRY AGAIN.");
            System.out.print("ENTER YOUR PIN: ");
            entry = keyboard.nextInt();
        }

        System.out.println("\nPIN ACCEPTED. YOU NOW HAVE ACCESS TO YOUR ACCOUNT.");
    }
}

What You Should See
WELCOME TO THE BANK OF MITCHELL.
ENTER YOUR PIN: 90210

INCORRECT PIN. TRY AGAIN.
ENTER YOUR PIN: 11111

INCORRECT PIN. TRY AGAIN.
ENTER YOUR PIN: 12345

PIN ACCEPTED. YOU NOW HAVE ACCESS TO YOUR ACCOUNT.

Notice what happens when we type the correct PIN on the first try:

WELCOME TO THE BANK OF MITCHELL.
ENTER YOUR PIN: 12345

PIN ACCEPTED. YOU NOW HAVE ACCESS TO YOUR ACCOUNT.

What You Should Do on Your Own

Assignments turned in without these things will receive no credit.

1. How is a while loop similar to an if statement?
2. How is a while loop different from an if statement?
3. Inside the while loop, why isn’t there an int in front of the line entry = keyboard.nextInt()?
4. Delete the line entry = keyboard.nextInt(); from inside the while loop. What happens? Why?
5. (Put the entry = keyboard.nextInt(); back before you turn in the assignment.)