title: How to get the first Element of an array - jQuery
body: <p>I have a multidimensional and I want to get the first element of the 2nd dimension.</p>
  
  <pre><code>myArray[0]
  </code></pre>
  
  <p>is my 2nd dimension.
  I am not able to use</p>
  
  <pre><code>myArray[0][0]
  </code></pre>
  
  <p>because I don't know the key of the 2nd dimenson (key = userID).
  Any idea how to get the first element without knowing the key?</p>