原生js添加class

function hasClass(obj, cls) {
    return obj.className.match(new RegExp('(\\s|^)' + cls + '(\\s|$)'));
}

function addClass(obj, cls) {
    if (!this.hasClass(obj, cls)) obj.className += " " + cls;
}

function removeClass(obj, cls) {
    if (hasClass(obj, cls)) {
        var reg = new RegExp('(\\s|^)' + cls + '(\\s|$)');
        obj.className = obj.className.replace(reg, ' ');
    }
}

function toggleClass(obj,cls){
    if(hasClass(obj,cls)){
        removeClass(obj, cls);
    }else{
        addClass(obj, cls);
    }
}

function toggleClassTest(){
    var obj = document. getElementById('test');
    toggleClass(obj,"testClass");
}

-------------------------------

parent.className = " newDiv"; 

//改变classname