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.