add and remove class in javascript code example

Example 1: javascript remoev css class

//remove a css class from an element
document.getElementById("myElementID").classList.remove("class_name");

Example 2: es6 add and remove class

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

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

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

Example 3: how to remove an class in javascript

document.getElementsByClassName("legend").style.display="none";