Htykuut

You can do this using the filter() function:

$(".a").filter(".b")

For the case

<element class="a">

  <element class="b c">

  </element>

</element>

You would need to put a space in between .a and .b.c

$('.a .b.c')

The problem you're having, is that you are using a Group Selector, whereas you should be using a Multiples selector! To be more specific, you're using $('.a, .b') whereas you should be using $('.a.b').

For more information, see the overview of the different ways to combine selectors herebelow!

Group Selector : ","

Select all <h1> elements AND all <p> elements AND all <a> elements :

$('h1, p, a')

Multiples selector : "" (no character)

Select all <input> elements of type text, with classes code and red :

$('input[type="text"].code.red')

Descendant Selector : " " (space)

Select all <i> elements inside <p> elements:

$('p i')

Child Selector : ">"

Select all <ul> elements that are immediate children of a <li> element:

$('li > ul')

Adjacent Sibling Selector : "+"

Select all <a> elements that are placed immediately after <h2> elements:

$('h2 + a')

General Sibling Selector : "~"

Select all <span> elements that are siblings of <div> elements:

$('div ~ span')

Just mention another case with element:

E.g. <div id="title1" class="A B C">

Just type: $("div#title1.A.B.C")

Vanilla JavaScript solution:-

document.querySelectorAll('.a.b')

For better performance you can use

$('div.a.b')

This will look only through the div elements instead of stepping through all the html elements that you have on your page.

Group Selector

body {font-size: 12px; }

body {font-family: arial, helvetica, sans-serif;}

th {font-size: 12px; font-family: arial, helvetica, sans-serif;}

td {font-size: 12px; font-family: arial, helvetica, sans-serif;}

Becomes this:

body, th, td {font-size: 12px; font-family: arial, helvetica, sans-serif;}

So in your case you have tried the group selector whereas its an intersection

$(".a, .b") 

instead use this

$(".a.b") 

You do not need jQuery for this

In Vanilla you can do :

document.querySelectorAll('.a.b')

You can use getElementsByClassName() method for what you want.

var elems = document.getElementsByClassName("a b c");

elems[0].style.color = "green";

console.log(elems[0]);

<ul>

  <li class="a">a</li>

  <li class="a b">a, b</li>

  <li class="a b c">a, b, c</li>

</ul>

This is the fastest solution also. you can see a benchmark about that here.