Question

I keep getting my code caught in an infinite while loop.

It is nothing to advanced, but i can not figure it out for the life of me!

Someone Please help

I have purplosely just re created the specific error without all of the if statements i have in my actual program.

    package bs;

    import java.util.InputMismatchException;
    import java.util.Scanner;

    public class bs {

        public static void main(String[] args) {

            Scanner sc = new Scanner(System.in);

            boolean continueVar = true;

            while (continueVar) {

                try {
                    System.out.println("Enter Something");
                    int input = sc.nextInt();

                } catch (InputMismatchException i) {
                    System.out.println("What the f***?");
                    continueVar = true;
                }
            }


        }
    }

The infinite loop occurs when the Input mismatch exception is caught. I would think that it would atleast ask the user to re enter their input but instead of doing that it just continues in the loop as so:

    run:
    Enter Something
    df
    What the f***?
    Enter Something
    What the f***?
    Enter Something
    What the f***?

It acts like it is just ignoring the scanner object sc?!

Answer 1

No the scanner is not skipped, it’s just starting at the beginning of the input. From the JavaDoc:

If the translation is successful, the scanner advances past the input that matched.

This means if the conversion isn’t successfull the scanner won’t advance. You’d thus have to manually skip the incorrect input using just next().

Edit: you might want to check for hasNextInt() before trying to read the input.