title: jquery - Can I count input name first slot of array 2 dimension?
body: <p>Hello I want to count the first <code>[]</code>  of input name</p>
  
  <pre><code>&lt;input type="text" name="Hello[a][]"&gt;
  &lt;input type="text" name="Hello[a][]"&gt;
  &lt;input type="text" name="Hello[a][]"&gt;
  &lt;input type="text" name="Hello[b][]"&gt;
  &lt;input type="text" name="Hello[b][]"&gt;
  &lt;input type="text" name="Hello[c][]"&gt;
  &lt;input type="text" name="Hello[c][]"&gt;
  &lt;input type="text" name="Hello[c][]"&gt;
  &lt;input type="text" name="Hello[c][]"&gt;
  </code></pre>
  
  <p>the result of count should be <strong>3</strong>   (a, b ,c) 
  How could I do with jquery or javascript?</p>