title: Explode string into nested array
body: <p>I would like to convert these strings into a combined nested array:</p>
  
  <pre><code>array(
      'item1:item2:itemx',
      'item1:item2:itemy',
      'itemz'
  )
  </code></pre>
  
  <p>To</p>
  
  <pre><code>array(
      'item1' =&gt; array(
          'item2' =&gt; array(
              'itemx' =&gt; array(),
              'itemy' =&gt; array(),
          )
      )
      'itemz' =&gt; array()
  )
  </code></pre>
  
  <p>Is there a way to do this with explode/foreach loop?</p>