document.querySelector()
Find the first matching element on a page.
// The first div
var elem = document.querySelector('div');
// The first div with the .bg-red class
var elemRed = document.querySelector('.bg-red');
// The first div with a data attribute of snack equal to carrots
var elemCarrots = document.querySelector('[data-snack="carrots"]');
// An element that doesn't exist
var elemNone = document.querySelector('.bg-orange');