javascript obtient un élément par classe
var elementsArray = document.getElementsByClassName("someclassname");
Grepper
var elementsArray = document.getElementsByClassName("someclassname");let elementsArray = document.getElementsByClassName("className");
// OR
let element = document.querySelector(".className");document.getElementsByClassName('Name');var elements = document.querySelector(".class");var elements = document.getElementsByClassName(names); // or:
var elements = rootElement.getElementsByClassName(names);var y = document.getElementsByClassName('foo');
var aNode = y[0];