title: Extracting GTIN (regex)
body: <p>I'm looking to extract GTIN codes from documents, they're 8, 12, 13 or 14 digit numbers. So I'm doing this:</p>
  
  <pre><code>$html = '8 digit 12345678 and now 12 digit 123456789012';
  
  $extractGTIN = '/\d{7}$|^\d{11}$|^\d{12}$|^\d{13}/mi'; 
  preg_match_all($extractGTIN, $html, $barcodes);
  
  echo print_r ($barcodes, 1);    
  </code></pre>
  
  <p>... but unexpectedly, it returns:</p>
  
  <pre><code>Array
  (
      [0] =&gt; Array
          (
              [0] =&gt; 6789012
          )
  
  )
  </code></pre>