Question

Today, someone attended me to bad use of the return keyword in Java. I had written a simple for loop to validate that something is in an array. Supposing array is an array of length n, this was my code:

for (int i = 0; i < array.length; ++i) {
    if (array[i] == valueToFind) {
        return true;
    }
}
return false;

Now someone told me that this is not very good programming because I use the return statement inside a loop and this would cause garbage collection to malfunction. Therefore, better code would be:

int i = 0;
while (i < array.length && array[i] != valueToFind) {
    ++i;
}
return i != array.length;

The problem is that I can’t come up with a proper explenation of why the first for loop isn’t a good practice. Can somebody give me an explanation?

Answer 1

Now someone told me that this is not very good programming because I use the return statement inside a loop and this would cause garbage collection to malfunction.

That’s incorrect, and suggests you should treat other advice from that person with a degree of skepticism.

The mantra of “only have one return statement” (or more generally, only one exit point) is important in languages where you have to manage all resources yourself – that way you can make sure you put all your cleanup code in one place.

It’s much less useful in Java: as soon as you know that you should return (and what the return value should be), just return. That way it’s simpler to read – you don’t have to take in any of the rest of the method to work out what else is going to happen (other than finally blocks).