Javascript function not returning from within a loop

Question

I have a JavaScript function as:

function nodeExists(text, ancestor, tree, generationCount) {

tree.findByText(text).each(function (index, element) {

    var gen = generationCount;
    var currNode = element;
    while (gen !== 1) { // 1: node itself

        currNode = tree.parent(currNode);
        gen--;
    }

    if (tree.text(currNode) === ancestor)
        return currNode; // Even if condition is met, control continues looping       
})       

return null;
//return ($.inArray(ancestor, gArr) !== -1) ? true : false;
}

While debugging function not exiting from a loop even if tree.text(currNode) === ancestor is truthy. Is Jquery .each causing it. Please help me.

First question, what's being passed for generationCount? I would also suggest that you don't do while (gen !== 1) but instead, while (gen > 1), just in case something goes wrong. — Scott Sauyet
– Scott Sauyet, Commented Sep 19, 2013 at 11:51
Only returning false will stop the iteration with each, use break or return false so element == currNode — AlexP
– AlexP, Commented Sep 19, 2013 at 11:52
@Scott generationCount is integer > 1. While while(gen > 1) works good, what is its benefit over while(gen !== 1), some kind of cuteness or performance reasons? — Bishnu Rawal
– Bishnu Rawal, Commented Sep 19, 2013 at 14:33
@Binbsr: The advantage is that if this is somehow called with a bad value of generationCount, such as 0 or -73, or "abc", the code won't get stuck in an infinite loop. — Scott Sauyet
– Scott Sauyet, Commented Sep 19, 2013 at 17:13

Lloyd · Accepted Answer · 2013-09-19 11:51:45Z

6

From the jQuery documentation:

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.

You aren't returning false so the loop will continue.

answered Sep 19, 2013 at 11:51

Lloyd

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Comments

Peekmo · Accepted Answer · 2013-09-19 11:51:01Z

0

Did you try an alert instead of a return ? Perhaps your ancestor is not "===" but just "==" to your tree.text(currNode) ?

answered Sep 19, 2013 at 11:51

Peekmo

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1 Comment

Bishnu Rawal Over a year ago

I don't need alerts, since i am debugging it line by line :). And === is deliberate, since it is fast (don't need type conversions) than ==. Thanks anyway.

halkujabra · Accepted Answer · 2013-09-19 12:05:26Z

0

You will have to return 'false'. Otherwise, it will go to next iteration.

answered Sep 19, 2013 at 12:05

halkujabra

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1 Comment

Bishnu Rawal Over a year ago

Thanks, i already accepted the answer for nice advice, i can't vote you up (Sorry to my reputation score).

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