title: PHP preg_match split string separated by addition sign
body: <p>I'm confused about a <code>php</code> regex that needs to <strong>extract two queries</strong> separated by a <code>+</code> <strong>plus sign</strong> sentences from a search request (which may include numbers and/or special characters). </p>
  
  <p>Can anyone shed some light on this behaviour?</p>
  
  <pre><code>$string = 'string1+String-2';
  
  ([a-zA-Z0-9-_]+[a-zA-Z0-9-_])
  
  Array
  (
      [0] =&gt; string1
      [1] =&gt; string1
  )
  </code></pre>