title: how to hide all divs in jquery
body: <p>I have several divs:</p>
  
  <pre><code>&lt;div id="div-1"&gt;&lt;/div&gt;
  &lt;div id="div-2"&gt;&lt;/div&gt;
  &lt;div id="div-3"&gt;&lt;/div&gt;
  &lt;div id="div-4"&gt;&lt;/div&gt;
  </code></pre>
  
  <p>How can I hide them all with jquery. I used <code>$('#div').hide();</code> and did not work.</p>