jQuery.each() doesn't deal with arrays properly

[wmleler]

If you create an empty array and insert values into it, then use the jQuery.each() utility, it has an extra value with index 0 that was not inserted. Here is code to show the bug:

<code>

$(function () {

var p1 = []; var p2 = {};

p1[1] = 'one'; p1[2] = 'two';

p2[1] = 'one'; p2[2] = 'two';

$.each(p1, function(i, v) {

$('#output').append('+i+? '+v+'<br />');

}); $('#output').append('<br />'); $.each(p2, function(i, v) {

$('#output').append('+i+? '+v+'<br />');

});

});

Output is:

[0] undefined [1] one [2] two

[1] one [2] two

Note the extra value in the array with index 0. That should not be there. Tested on Safari and Firefox on Macintosh.

[wmleler]

small program to reproduce the bug

[dmethvin]

jQuery.each always processes an Array from 0 to length-1. The length property is managed by Javascript so it will equal the value of the highest numeric index plus 1. If you have a truly sparse array, you can always handle it with an object, as your example shows.

[wmleler]

Would be very nice if this were in the documentation. Something on the order of "each() iterates though arrays from 0 to length-1".

[dmethvin]

Done.

​http://docs.jquery.com/Utilities/jQuery.each

[wmleler]

Thanks very much!