How .sort () work in JavaScript? [duplicate]

This question already has a开发者_高级运维nswers here: Closed 11 years ago.

Possible Duplicate:

Javascript Array.sort implementation?

I want to know how .sort() works in JavaScript. What algorithm does it use?

function sortNumber(a, b) {
   return a-b;
}

var n = ["1", "5", "40", "2", "9", "3"];
document.write(n.sort(sortNumber));

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This question was answered here.

Mozilla uses merge sort, Webkit uses selection sort, and IE is closed-source so hard to tell.

The language specification states no requirement on what algorithm an implementation uses, and your code shouldn't really care about it too much.

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Number of comparisons for 100 element test array:

Safari 5 - 541
Opera 11.10 - 586
Firefox 4 - 601
IE 9 - 618
Chrome 9 - 783

And for 1000 element test array:

Safari 5 - 8700
Firefox 4 - 8998
Opera 11.10 - 9137
IE 9 - 11055
Chrome 9 - 11536

It does not describe an algorithm but still shows some interesting data.

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in Firefox 4 the elements are converted into Numbers and sorted this way. In your case this is ascending order.

I didn't test it in other browsers so far.