Question

I have several switch statements in a Java program. My question is, if I construct the switch statement similar to this:

switch (getNum()) {
    case 0: // do something
    case 1: // do something
    ...
}

where the variable to be switched is getting returned from an accessor method (aka ‘getter’ method), will the switch statement call getNum() every time it checks a case? Or will it assign a temporary variable to the int being returned from getNum() to check each case?

Answer 1

will the switch statement call getNum() every time it checks a case?

It doesn’t ‘check each case’ at all. It evaluates the expression once and jumps to the associated case immediately, via one of several techniques depending on the implementation.

Or will it assign a temporary variable to the int being returned from getNum() to check each case?

It doesn’t do that either: see above.