classlist react code example

Example 1: es6 add and remove class

let el = document.getElementById('container');

//remove class
el.classList.remove('first');

//remove class
el.classList.add('first');

Example 2: classList has class

if (document.body.classList.contains('thatClass')) {
    // do some stuff
}

Example 3: .classList

// .classList method returns an array of the classes attached to the element it is called with.
document.getElementById("myDIV").classList
// It returns
// [ 'className1', 'className2', ... ]