title: How can get length on checked checkbox array with jquery?
body: <p>I want to use jQuery to get the length of a checkbox array such as the following:</p>
  
  <pre><code>&lt;li&gt;&lt;input name="skills['11111']" class="skills" value="1" type="checkbox" /&gt;&lt;/li&gt;
  &lt;li&gt;&lt;input name="skills['22222']" class="skills" value="2" type="checkbox" /&gt;&lt;/li&gt;
  &lt;li&gt;&lt;input name="skills['33333']" class="skills" value="3" type="checkbox" /&gt;&lt;/li&gt;
  &lt;li&gt;&lt;input name="skills['44444444']" class="skills" value="4" type="checkbox" /&gt;&lt;/li&gt;
  </code></pre>
  
  <p><code>&lt;li&gt;&lt;input name="test['999999999']" class="tesst" value="4" type="checkbox" /&gt;&lt;/li&gt;</code></p>
  
  <p>Also, I have some field input checkbox diffirent name and I only want to get checkbox <code>name= skills</code></p>
  
  <p>In this case, the length will be 4.  How can I do this?</p>