btw ,there's a interesting topic ,too.

if you are doing array concat job, you could take a look for this.
http://jsfiddle.net/We9p9/1/

The keypoint is , even when you are using array.push ,

*ary.push(1,2,3,4,5);*
is still faster then
*ary.push(1);
ary.push(2);
ary.push(3);
ary.push(4);
ary.push(5);
*


2011/3/16 Diego Perini <[email protected]>:
> On Wed, Mar 16, 2011 at 12:14 PM, Rob Griffiths <[email protected]> wrote:
>>
>>> Length should return the value of the last index + 1, so in that case
>>> length will return 8
>>
>> I knew I should have checked before stating that.
>>
>> --
>> Rob Griffiths
>> http://bytespider.eu
>> @bytespider
>> https://github.com/bytespider
>>
>> --
>> To view archived discussions from the original JSMentors Mailman list:
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>>
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>> http://www.mail-archive.com/[email protected]/
>>
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>>
>
> I use the following to convert/concat NodeList to Array:
>
>  // concat elements to data array
>  concatList =
>    function(data, elements) {
>      var i = -1, element;
>      if (data.length === 0 && Array.slice)
>        return Array.slice(elements);
>      while ((element = elements[++i]))
>        data[data.length] = element;
>      return data;
>    },
>
> On older browsers this was the fastest "loop" among many browsers at
> the time I tested it and on newer browsers this is not used/necessary.
>
> I am not sure using Firefox "Array.slice" shortcut when "data" array
> is empty is worth it (nowadays) so the bare bone JS should be this:
>
>  // concat elements to data array
>  concatList =
>    function(data, elements) {
>      var i = -1, element;
>      while ((element = elements[++i]))
>        data[data.length] = element;
>      return data;
>    },
>
> At that time another interesting thing I observed was that Webkit
> based browser were also faster to access DOM element in the ancient
> way using the "nodelist.item(n)" notation (really much faster).
>
> The point is performances are improving at a fast pace in every
> browser engine so small speed improvements like these are becoming
> less and less relevant, it is still a funny exercise though :)
>
> --
> Diego
>
> --
> To view archived discussions from the original JSMentors Mailman list:
http://www.mail-archive.com/[email protected]/
>
> To search via a non-Google archive, visit here:
http://www.mail-archive.com/[email protected]/
>
> To unsubscribe from this group, send email to
> [email protected]
>

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