Switch statement resulting in java:240 (might not have been initialized)

Question

I am trying to store a value inside a variable depending on the input:

switch(pepperoni) {

    case 'Y':
    case 'y':
        topping1 = 1;
        break;

    case 'N':
    case 'n':   
        topping1 = 0;
        break;

    default: 

        {
    System.out.print("This is not a valid response, please try again \n");  
    System.out.print("Do you want Pepperoni? (Y/N): ");
    pepperoni = scan.next().charAt(0);
        break;
    }

I want the variable topping1 to store the value 1 if the input is 'Y' or 'y' and to store the value 0 if the input is 'N' or 'n'

If the input is neither 'Y', 'y', 'N' nor 'n' then I want it to repeat the question until a valid input is typed in.

The problem arises when I later in the program try to print the value 'because it might have not been initialized', which somewhat makes sense. (example below)

if(topping1 > 0)
    System.out.println("Pepperoni"); 

// 243: error: variable topping1 might not have been initialized

I do realize there are other ways to do this, but as I am really wanting to learn Java I try to understand as much of the fundamentals as possible. Therefore would I be really happy if someone could tell me why this not work and if there is a way to do this with a switch statement or quick fixes.

Answer 1

If pepperoni is not Y, y, N, or n, you never assign a value to topping1, because the default case never assigns it a value. E.g., if pepperoni is not one of those four values, then the flow of control skips the other two cases and goes to default, which never gives topping1 a value, so later when you try to use it, it's possible topping1 has never received a value at all.

The "workaround" is to correct the logic so that you never try to use topping1 without having assigned it a value. How you do that depends on logic you haven't shown us. You might assign it a value other than 0 or 1 (the values you assign in the other branches of the switch), for instance.