Elemento JavaScript por clase
var elementsArray = document.getElementsByClassName("someclassname");
Grepper
var elementsArray = document.getElementsByClassName("someclassname");var elements = document.querySelector(".class");var x = document.getElementsByClassName("example");
var i;
for (i = 0; i < x.length; i++) {
x[i].style.backgroundColor = "red";
}const whiteBoxes = document.getElementsByClassName("box-white")var y = document.getElementsByClassName('foo');
var aNode = y[0];