Breaking parent function of jQuery each function

Question

I have a $.each jQuery function sitting in a parent javascript function, how do I break the parent function upon a certain index (i)?

Answer 1

To break from one loop, just return false:

$('something').each(function() {
    if (need_to_break) {
        return false; // returning false stops the loop
    }
});

To break from / return from multiple each loops at once, just throw an exception:

var $break = {};
$('something').each(function() {
    try {
        $('something').each(function() {
            $('something').each(function() {
                $('something').each(function() {
                    throw $break;
                });
            });
        });
    } catch(E) {
        if (E != $break) throw E;
    }
});

And catch it in the loop you want to return to.

This is how Prototype.js implements break, in their Enumerable.each(), for instance.

A more conventional solution:

var do_break = false;
$('something').each(function() {
    $('something').each(function() {
        $('something').each(function() {
            $('something').each(function() {
                do_break = true;
                return false;
            });
            if (do_break) {
                return false;
            }
        });
        if (do_break) {
            return false;
        }
    });
    if (do_break) {
        return false;
    }
});

Answer 2

From the sound of it, you have something like this:

function outer(someParam) {
    $.each(someParam, function(i) {
        // do something with each value in someParam
    });
}

You want to return from outer when the inner loop reaches a certain value. You can't do this in one go. The key point is that doing return false from the $.each callback ends the "loop". You can then set a variable to return conditionally if you need that:

function outer(someParam) {
    var returnNow = false;
    $.each(someParam, function(i) {
        if (i === 5) {
            returnNow = true;
            return false;
        }

        // do something with each value in someParam
    });

    if (returnNow) {
        return;
        // return immediately
    }

    // do some other action if you want to
}