I have a method that returns a int, and it tells me i'm missing a return statement. Can this be fixed without rewriting the method?

Question

This is the method. As you can see, all of the if statements have a return in them so I understand why it is not recognizing the output, but is there any way to fix this?

private int bounds(int x, int y) {
        if (x == -1) {
            if (y == -1) {
                return life[130][70];
            }
            else if (y == 71) {
                return life[130][0];
            }
            if (0 <= y && y <= 70) {
                return life[130][y];
            }
        }
        else if (x == 131) {
            if (y == -1) {
                return life[0][70];
            }
            else if (y == 71) {
                return life[0][0];
            }
            if (0 <= y && y <= 70) {
                return life[0][y];
            }
        }
        if (0 <= x && x <= 130) {
            if (y == -1) {
                return life[x][70];
            }
            else if (y == 71) {
                return life[x][0];

            }
            if (0 <= y && y <= 70) {
                return life[x][y];
            }
        }
    }

Answer 1

Ask yourself what your method would return if x is -2 for example.

Meaning: the compiler tells you that there are paths through that method that don't see a return statement. Simply: believe the compiler.

You could fix the problem by adding one final return statement after your if blocks.

But the real answer: you should never write code that turns that complicated. The above is a maintenance nightmare. It should be refactored.

Answer 2

you need to add a default return to the end of your function, if not one of the if statement is true

Answer 3

It is possible to fix the missing return statement compilation error without rewriting the method by:

1. Throwing a RuntimeException (if only some inputs are valid).
2. Returning a default value at the end (if all inputs are valid).

In the existing logic, negative integers other than -1 are not handled (same with upper bounds for x and y). If inputs which are not currently handled are invalid, you may do something like:

private int bounds(int x, int y) {
    ...
    (Existing logic)
    ...
    throw new IllegalArgumentException("Bad input");
}