title: Uncaught Typo error Cannot read property each of null
body: <p>I am trying to find a checkbox from the page which contains id that starts with the specific text <code>sku_cat</code>. I use this below function. But it is not working. I am getting an error 'Uncaught Typo error Cannot read property each of null.</p>
  
  <p>HTML Code:</p>
  
  <pre><code>&lt;input type="checkbox" name="sku[]" id="sku_cat123_blue" value="sku123"&gt;
  &lt;input type="checkbox" name="sku[]" id="sku_cat123_red" value="sku124"&gt;
  &lt;input type="checkbox" name="sku[]" id="sku_cat110_blue" value="sku125"&gt;
  &lt;input type="checkbox" name="sku[]" id="sku_cat115_blue" value="sku126"&gt;
  </code></pre>
  
  <p>Jquery script: </p>
  
  <pre><code>var category=$("input[type='checkbox'][id^='sku_cat']:checked").each();
  </code></pre>