Question

I have seen some developers place a return at the end of their JavaScript functions like this:

$(".items").each(function(){
    mthis = $(this);
    var xposition = some .x() position value;
    if(xposition < 0){
        mthis.remove();
        return;
    }
});

Is having a return even necessary? I know that return false cancels out of a loop early and I know that return x, returns a value, but having just return??? What does that mean?

Sorry – I forgot to put an end } at the very end of the code. the return is in the if conditional.

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New Update – just discovered that the intent of the loop was to cancel out the nth .item that entered the loop. so return false is my replacement for a simple return; (which means undefined anyway). Thanks everyone for the help!

Answer 1

Your example is specific for how jQuery.each handles the return values from a loop function. From the docs:

We can break the $.each() loop at a particular iteration by making the
callback function return false. Returning non-false is the same as a
continue statement in a for loop; it will skip immediately to the next
iteration.

So there you have it, returning anything else than false makes no difference, it will just move on to the next iteration. false, however, breaks the loop.

Note that return; is exactly the same as return undefined;.