jQuery Selector Performance Test
HTML
<div class="foo"></div>
<span class="foo"></span>
JavaScript
var start, end, i;
start = new Date();
for(i = 0; i < 100000; i++){
$("span.foo");
}
end = new Date();
$("span.foo").html(end - start);
start = new Date();
for(i = 0; i < 100000; i++){
$(".foo");
}
end = new Date();
$("div.foo").html(end - start);