CODEWITHSUNDEEP
javascriptjquerymemory-leaksclosures
jscoot
jscoot

Reputation: 2109

does this jQuery code snippet cause any memory leak?

I am wondering if the following jquery code causes any memory leak:

$( function() {                 
  var parent=$('table#mytable tbody').get(0);
  $('tr:last', parent).click(function(){...});
});

For my understanding, $('tr:last', parent) is the last row which is the DOM object, but in the anonymous function, the closure has this DOM object in scope, so there is a circular reference between DOM and js objects.

But if it really has leak, then I can see there are many such kind of code in the popular book "jQuery in Action" published by Manning. It is harmful "best practice" in jQuery coding?

But i don't know if my understanding is correct. I hope your comments and corrections. Thanks!

Upvotes: 4

Views: 2570

Answers (3)

umassthrower
umassthrower

Reputation: 1397

The previously submitted answers (from 3 years ago, sigh) are wrong. While jQuery 1.0 - 1.2 would leak here, looking at the version of jQuery from when this question was asked http://download.oldapps.com/jquery/jquery-1.3.js the following line was included in the function which adds all event listeners: 

        // Nullify elem to prevent memory leaks in IE
    elem = null;

Which is the exact leak prevention suggestion from the linked documentation.

Upvotes: 0

KooiInc
KooiInc

Reputation: 122926

IE is leak prone. You can test your code for leaks in IE with Microsofts javascript memory leak detector.

Firefox can leak too. This article explains why. There is also a leak detector plugin for Firefox (haven't tested it yet).

Upvotes: 1

serioys sam
serioys sam

Reputation: 2051

This code will cause memory leak in internet explorer 6 and internet explorer 7 not in other browser please refer these aritcles by Douglas Crockford and IBM Devloper Site

Upvotes: 2

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