JSFiddle - React, Tailwind, and code Playground

HTML

<div class="crazy one">Text 1</div>
<div class="crazy two">Text 2</div>
<div class="crdazy one">Different Text</div>
<div class="crazy three">Text 4</div>
<div class="crazy aaa one">Text 5</div>

JavaScript

function findByClass(classes) {
    var elems = document.getElementsByTagName('*');
    var matches = classes.split(' ');
    var resp = [];
    pula:
    for (var i = 0; i < elems.length; i++) {
        for (var j = 0; j < matches.length; j++) {
            if((" "+elems[i].className+" ").indexOf(" "+matches[j]+" ") < 0) {
                continue pula;
            }
        }
        resp.push(elems[i]);
    }
    return resp;
}

window.onload = function () {
    var elementos = findByClass("crazy one");
    for (var i = 0; i < elementos.length; i++) {
        console.log(elementos[i].innerHTML);
    }
}