My implementation of `getElementsByClass()`

getClass.js

function getClass(c) {
    var l = document.getElementsByTagName('*');
    var x = new Array();
    
    for(var i = 0; i < l.length; i++) {
        if(l[i].classList !== undefined && l[i].classList.contains(c)) {
            x.push(l[i]);
        }
    }

    return x;
}