javascript - jQuery: Is it possible to select elements with only one class from among elements with, potentially, up to 3 classes?

Question

For example, say I have the following:

<span class="a b c">Has class a, b, and c</span>  
<span class="a">Has class a</span>  
<span class="b c">Has class b and c</span> 
<span class="a c">Has class a and c</span> 
<span class="a c">Has class a and c</span> 
<span class="a">Has class a</span>

Now, suppose I want to select all elements that have only class a.
Meaning only the second and last spans would get selected.
Is there a simple way to do this?

Answer 1

$('.a').not('.b, .c')

This will select all elements with class a that do not have b or c. However, they could still have class d, e, etc. Use Phil's answer if you really only want elements with no class other than a.