Pure js hasClass vs jQuery hasclass

JavaScript performance comparison

Revision 14 of this test case created


Additional comparison of className and getAttribute("class")

Preparation code

<div class=" this is just a test case mother someClass " id="someElement"></div>
  var el = document.getElementById('someElement');
  function hasClass(el, selector) {  
   return (el.className).indexOf(" "+selector+" ")>-1

  function hasClass2(el, selector) {
   if (("" + el.className + "").replace(/[\n\t]/g, " ").indexOf(" " + selector + " ") > -1) {
    return true;
   return false;

function hasClass3(el, selector) {
   if (el.className.match("\b"+selector+"\b")){return true;}return false;}

function hasClass4(el, selector) {
   var pattern = '/(.*)(' + selector + ')(.*)/gi';
      return el.className.replace(pattern , '$2') != '';


Preparation code output

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Testing in unknown unknown
Test Ops/sec
hasClass3(el, 'someClass'); 
Pure JS (className)
hasClass(el, 'someClass');
Pure JS (getAttribute)
hasClass2(el, 'someClass');
PureJS replace
hasClass4(el, 'someClass');

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1 comment

Kelly Miyashiro commented :

hasClass only works if you write out all your class names with spaces around them...

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