title: how to replace ... between a word where one part is numeric the other is'int?
body: <p>how can i put a space between a word where one part is numeric the other is'int? like so:</p>
  
  <pre><code>$string = "this is a 2000px height photo";
  $string = preg_replace('???',' //1',$string);
  echo $string; //this is a 2000 px height photo
  </code></pre>
  
  <p>can someone help me? thanks!</p>