原生js給DOM元素添加一個或者多個類名

 

// 覆蓋原來的樣式
document.getElementById("test").setAttribute("class","test1");
var dom=document.getElementsByClassName("test")[0].setAttribute("class","test1");
// 追加樣式不覆蓋原來的樣式
document.getElementById("test").classList.add("test1");
document.getElementById("test").classList.add("test1","test2","test3");
var dom=document.getElementsByClassName("test")[0].classList.add("test1");
var dom=document.getElementsByClassName("test")[0].classList.add("test1","test2","test3");