Using a Try / Catch in a while loop

Question

I'm asking my user to input via regex format "ABC-1234" otherwise an IllegalArgumentException is thrown. I would like to keep asking for the correct input (I'm thinking while or do while with a boolean variable set to false while input is incorrect...) how would I do that with a try / catch?

Here's what I have thus far. Thanks!

try {
            Scanner in = new Scanner (System.in);

            System.out.println("Please enter id: ");
            String id = in.nextLine();

            Inventory i1 = new Inventory (id, "sally", 14, 2, 2);
            System.out.println(i1);

        } catch (Exception ex) {

             System.out.println(ex.getMessage());

        }

score 1 · Accepted Answer · answered May 14 '16 at 14:57

Obviously, you need some kind of loop and you need some mechanism to break out of the loop on success. Supposing IllegalArgumentException is thrown from Inventory constructor, your solution can simply be:

while (true) {
    try {
        // ...
        Inventory i1 = new Inventory(id, "sally", 12, 2, 2);
        System.out.println(i1);
        break; // or return i1 if you enclose this snippet in a function
    } catch (Exception ex) {
        // ...
    }
}

Using a Try / Catch in a while loop

1 Answers1