title: Key names of associative arrays
body: <p>I have a nested associative array like this:</p>
  
  <pre><code>$inputTypes= array( 
      "natural" =&gt; array(
          "text",
          "password",
          "textarea",
          "radio",
          "checkbox",
          "file"
      ),
      "hybrid" =&gt; array(
          "image",
          "date" ,
          "url",
          "email"
      )
  );
  </code></pre>
  
  <p>I want to print its key names, applying code shown below:</p>
  
  <pre><code>foreach ($inputTypes as $inputs){
      echo key($inputTypes).'&lt;br&gt;';
  }
  </code></pre>
  
  <p>but i get this output</p>
  
  <pre><code>hybrid
  hybrid
  </code></pre>
  
  <p>How can i get name of each keys, thanks.</p>