Javascript loop performance

[hobeau]

Here's an article I wrote awhile back about javascript loop performance when iterating through the DOM.

 

http://www.solutionbot.com/2008/05/14/javascript-loop-performance/

 

I thought it was interesting to see the differences between IE and all the rest. IE has a severely slow javascript engine and it does not compensate for issues such as this as do other browsers. Keeping your .length function outside of your loops isn't just a 'best practice', it can be the difference between a high performance DHTML app or a sluggish one. Just thought I'd share.

[Adam]

Interesting. I wasn't even aware it was slower. IE7 results are shocking! Do you have the script available for people to test on their own machines?

 

A

[hobeau]

There is a link on the post but you can get it here http://www.solutionbot.com/wp-content/uploads/2008/05/test.htm

[Adam]

Ah okay.. Results from IE8 and FF3 on my machine:

 

IE8

Test 1: 2230

Test 2: 71

 

FF3

Test 1: 50

Test 2: 67

 

 

 

[Philip]

Wow! That is insane, the difference is just unbelievable

 

IE7

Test 1: 25,516

Test 2: 61

 

FF3

Test 1: 55

Test 2: 28

 

Chrome

Test 1: 14

Test 2: 6