js get class of element code example

Example 1: javascript get element by class

var elementsArray = document.getElementsByClassName("someclassname");

Example 2: js add class

var element = document.getElementById('element');
element.classList.add('class-1');
element.classList.add('class-2', 'class-3');
element.classList.remove('class-3');

Example 3: get element by class

var elements = document.getElementsByClassName(names); // or:
var elements = rootElement.getElementsByClassName(names);

Example 4: javascript get class name

document.getElementById("myDIV").className = "mystyle";

Example 5: js get class property

let element = document.querySelector('.preset');
let style = getComputedStyle(element);
let bg = style.backgroundColor;