ID vs Classes

JavaScript performance comparison

Test case created

Preparation code

<input id="one" class="select">
<input id="two" class="select">
<input id="three" class="select">
<input id="four" class="select">
<input id="five" class="select">
<input id="six" class="select">
<input id="seven" class="select">
<input id="eight" class="select">
<input id="nine" class="select">
<input id="ten" class="select">

Preparation code output

Test runner

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Java applet disabled.

Testing in unknown unknown
Test Ops/sec
document.getElementById('one').disabled = true;
document.getElementById('two').disabled = true;
document.getElementById('three').disabled = true;
document.getElementById('four').disabled = true;
document.getElementById('five').disabled = true;
document.getElementById('six').disabled = true;
document.getElementById('seven').disabled = true;
document.getElementById('eight').disabled = true;
document.getElementById('nine').disabled = true;
document.getElementById('ten').disabled = true;
QSA id
var es = ['one','two','three','four','five','six','seven','eight','nine','ten'];
for(var i=0,l=es.length;i<l;i++) {
document.getElementById(es[i]).disabled = true;

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