title: preg_match_all into simple array
body: <p>I have preg_match_all function:</p>
  
  <pre><code>preg_match_all('#&lt;h2&gt;(.*?)&lt;/h2&gt;#is', $source, $output, PREG_SET_ORDER);
  </code></pre>
  
  <p>It's working as intended, BUT the problem is, it preg_matches all items twice and into a huge multi dimensional array like this for example where it, as intended, preg_matched all 11 items needed, but twice and into a multidimensional array:</p>
  
  <pre><code>Array
  (
      [0] =&gt; Array
          (
              [0] =&gt; &lt;h2&gt;10. &lt;em&gt;Cruel&lt;/em&gt; by St. Vincent&lt;/h2&gt;
              [1] =&gt; 10. &lt;em&gt;Cruel&lt;/em&gt; by St. Vincent
          )
  
      [1] =&gt; Array
          (
              [0] =&gt; &lt;h2&gt;9. &lt;em&gt;Robot Rock&lt;/em&gt; by Daft Punk&lt;/h2&gt;
              [1] =&gt; 9. &lt;em&gt;Robot Rock&lt;/em&gt; by Daft Punk
          )
  
      [2] =&gt; Array
          (
              [0] =&gt; &lt;h2&gt;8. &lt;em&gt;Seven Nation Army&lt;/em&gt; by the White Stripes&lt;/h2&gt;
              [1] =&gt; 8. &lt;em&gt;Seven Nation Army&lt;/em&gt; by the White Stripes
          )
  
      [3] =&gt; Array
          (
              [0] =&gt; &lt;h2&gt;7. &lt;em&gt;Do You Want To&lt;/em&gt; by Franz Ferdinand&lt;/h2&gt;
              [1] =&gt; 7. &lt;em&gt;Do You Want To&lt;/em&gt; by Franz Ferdinand
          )
  
      [4] =&gt; Array
          (
              [0] =&gt; &lt;h2&gt;6. &lt;em&gt;Teenage Dream&lt;/em&gt; by Katie Perry&lt;/h2&gt;
              [1] =&gt; 6. &lt;em&gt;Teenage Dream&lt;/em&gt; by Katie Perry
          )
  
      [5] =&gt; Array
          (
              [0] =&gt; &lt;h2&gt;5. &lt;em&gt;Crazy&lt;/em&gt; by Gnarls Barkley&lt;/h2&gt;
              [1] =&gt; 5. &lt;em&gt;Crazy&lt;/em&gt; by Gnarls Barkley
          )
  
      [6] =&gt; Array
          (
              [0] =&gt; &lt;h2&gt;4. &lt;em&gt;Kids&lt;/em&gt; by MGMT&lt;/h2&gt;
              [1] =&gt; 4. &lt;em&gt;Kids&lt;/em&gt; by MGMT
          )
  
      [7] =&gt; Array
          (
              [0] =&gt; &lt;h2&gt;3. &lt;em&gt;Bad Romance&lt;/em&gt; by Lady Gaga&lt;/h2&gt;
              [1] =&gt; 3. &lt;em&gt;Bad Romance&lt;/em&gt; by Lady Gaga
          )
  
      [8] =&gt; Array
          (
              [0] =&gt; &lt;h2&gt;2. &lt;em&gt;Pumped Up Kicks&lt;/em&gt; by Foster the People&lt;/h2&gt;
              [1] =&gt; 2. &lt;em&gt;Pumped Up Kicks&lt;/em&gt; by Foster the People
          )
  
      [9] =&gt; Array
          (
              [0] =&gt; &lt;h2&gt;1. &lt;em&gt;Paradise&lt;/em&gt; by Coldplay&lt;/h2&gt;
              [1] =&gt; 1. &lt;em&gt;Paradise&lt;/em&gt; by Coldplay
          )
  
      [10] =&gt; Array
          (
              [0] =&gt; &lt;h2&gt;Song That Get Stuck In Your Head YouTube Playlist&lt;/h2&gt;
              [1] =&gt; Song That Get Stuck In Your Head YouTube Playlist
          )
  
  )
  </code></pre>
  
  <p>How to convert this array into simple one and without those duplicated items? Thank you very much.</p>