Add a class to an element with javascript

Question

I was wondering if someone could help me. I'm trying to add .fancy-btn to the below using JavaScript.

<div class="button transparent_2">
<a class="extra-color-3" href="#">Get a quote</a>
</div>

I want .fancy-btn class added to the div container, but cant seem to figure out how to achieve is

Thanks

Answer 1

您需要使用.addClass() ：

$(".transparent_2").addClass('fancy-btn')

Answer 2

Here is a JavaScript only method:

var $a = document.getElementsByClassName("transparent_2");
//assuming there is only 1 element (or is the first)
$a[0].className += " fancy-btn";

JSFiddle

Answer 3

see here: https://stackoverflow.com/a/507157/3503886

Add a space plus the name of your new class to the className property of the element. First, put an id on the element so you can easily get a reference.

<div id="div1" class="someclass">
    <img ... id="image1" name="image1" />
</div>

Then

var d = document.getElementById("div1");
d.className = d.className + " otherclass";