Appropriate use of "return" in a method

Question

Migrating to Java quite some time back now I still haven't found the appropriate use of the 'return'-statement in a method.
In procedual languages there has always been an unwritten rule saying that a function should not have more than one 'return'-statement and that the 'return'-statement should always be the last line to be executed in the function.
Having seen a lot of source code by other Java programmers I was puzzled to see that a lot of programmers uses multiple return statments and furthermore use them to terminate loops, etc.
Example, binary search find method
while ( current.key != key ){
    if ( key < current.key){
        current = current.leftChild;
    else{
        current = current.rightChild;
    if (current == null){
        return null;
return current;As you can see in the example, 'return' is used in the middle of the loop to both return a value and to stop the rest of the processing in the method.
Is there any recommended practise on using 'return'? Personally I don't like the idea of having more than one return statement in my code as the code can end up being irrational.
What do guys think in the forum?
Kind regards,
Allan

Answer 1

Sylvia is probably right about the origin of that practice, memory leaks were a huge problem (and are to a lesser extent in Java). You really shouldn't avoid doing multiple returns to avoid memory leaks in C++ even. Usually when you allocate memory that you're expecting to simply disapear at the end of a function, you're going to allocate it as a stack variable, rather than using new, and it will be removed when it falls out of scope. There are some functions, like strcpy, and strdup, to name a few, that will allocate memory, and it's possible you could return out without removing that data. I find if this is likely to happen, the user probably wasn't thinking about releasing the data to begin with, and could just as easily return at the end of the function without releasing the memory, as he/she would at any point inside the function. I'd hope that you'd be using this newly created memory for some purpose before returning, so I would assume it's use would be complete before you left that function, and definitely it would be ready to be deleted.
-Jason Thomas.