title: jQuery: Is it possible to select elements with only one class from among elements with, potentially, up to 3 classes?
body: <p>For example, say I have the following:  </p>
  
  <pre><code>&lt;span class="a b c"&gt;Has class a, b, and c&lt;/span&gt;  
  &lt;span class="a"&gt;Has class a&lt;/span&gt;  
  &lt;span class="b c"&gt;Has class b and c&lt;/span&gt; 
  &lt;span class="a c"&gt;Has class a and c&lt;/span&gt; 
  &lt;span class="a c"&gt;Has class a and c&lt;/span&gt; 
  &lt;span class="a"&gt;Has class a&lt;/span&gt;
  </code></pre>
  
  <p>Now, suppose I want to select all elements that have <b>only</b> class a.<br>
  Meaning only the second and last <code>span</code>s would get selected.<br>
  Is there a simple way to do this?</p>