JQuery Find #ID, RemoveClass and AddClass

问题

I have the following HTML

<div id="testID" class="test1">
        <img id="testID2" class="test2" alt="" src="some-image.gif" />
    </div>

I basically want to get to #testID2 and replace .test2 class with .test3 class ?

I tried

jQuery('#testID2').find('.test2').replaceWith('.test3');

But this doesn't appear to work ?

Any ideas ?

回答1:

jQuery('#testID2').find('.test2').replaceWith('.test3');

Semantically, you are selecting the element with the ID testID2, then you are looking for any descendent elements with the class test2 (does not exist) and then you are replacing that element with another element (elements anywhere in the page with the class test3) that also do not exist.

You need to do this:

jQuery('#testID2').addClass('test3').removeClass('test2');

This selects the element with the ID testID2, then adds the class test3 to it. Last, it removes the class test2 from that element.

回答2:

$('#testID2').addClass('test3').removeClass('test2');

jQuery addClass API reference

回答3:

Try this

$('#testID').addClass('nameOfClass');

or

$('#testID').removeClass('nameOfClass');

回答4:

.....

$("#testID #testID2").removeClass("test2").addClass("test3");

Because you have assigned an id to img too, you can simply do this too:

$("#testID2").removeClass("test2").addClass("test3");

And finally, you can do this too:

$("#testID img").removeClass("test2").addClass("test3");

回答5:

corrected Code:

jQuery('#testID2').addClass('test3').removeClass('test2');

来源：https://stackoverflow.com/questions/2407179/jquery-find-id-removeclass-and-addclass