Run results for: getElementById vs querySelector ID vs getElementsByClassName vs querySelectorAll

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:77.0) Gecko/20100101 Firefox/77.0

Browser: Firefox 77

Operating system: Mac OS X 10.15

Device Platform: Desktop

Date tested: 4 years ago

HTML Preparation code:

<div id="test_element_id" class="test_element_class"></div>

Tests:

getElementById
var el = document.getElementById('test_element_id'); var className = el.className;
querySelector
var el = document.querySelector('#test_element_id'); var className = el.className;
getElementsByClassName
var el = document.getElementsByClassName('test_element_class')[0]; var className = el.className;
querySelectorAll
var el = document.querySelectorAll('.test_element_class')[0]; var className = el.className;
querySelector class
var el = document.querySelector('.test_element_class'); var className = el.className;