jQuery check if Attr Class exists?

Question

How do I determine if the .attr('class') exists?

I am using this code:

if(jQuery(this).attr('class') != undefined && jQuery(this).hasClass('myclass')) {
  //Do something
}

It doesn't seem to work.

Answer 1

It depends on what you want. Do you want to check if an element has the class attribute, such as:

<div class></div>
<div class=""></div>
<div class="abc"></div>

If so, use:

if ($('div').attr('class') != undefined)...

If you're trying to check if the element has a specific class, use:

if ($('div').hasClass('abc'))...

Answer 2

Try this..

 if(jQuery('#id1').attr('class') =="") { alert($('#id1').attr('class')); } 

<div id="id1">test</div>

Answer 3

您可以通过在jquery对象上调用'length'来检查是否存在具有任何类的元素。

$('.myclass').length

Answer 4

如果属性类不存在，则返回值为null或空字符串。

Answer 5

this code works actually: fiddle

HTML:

<div></div>
<div class="myclass"></div>
<div class="blah"></div>
<div></div>
<div class="myclass"></div>
<div class="myclass"></div>
<div></div>
<div class="myclass andAnotherClass"></div>​

JS:

$("div").each(function(){
if(jQuery(this).attr('class') != undefined && jQuery(this).hasClass('myclass')) {
  jQuery(this).html("I have it");
      } else {
          jQuery(this).html("I don't have it");
      }
});​