title: remove characters before and after
body: <p>Here, I am using <code>strstr</code> to remove after characters and <code>substr</code> is used to remove before character. But how to remove all characters before and after at once ?</p>
  
  <p>I need to get only <code>80</code> from this variable <code>$mrk = 'Science-80_John'</code> omitting <code>Science</code> and <code>John</code>. </p>
  
  <p>What I am doing</p>
  
  <pre><code>$mrk = 'Science-80_John';
  
  $mark = substr($mrk,strpos($mrk,'-')+1);
  //output: 80_John
  
  echo strstr($mark, '_', true);
  //output: 80
  </code></pre>
  
  <p>Any other short or best way ?</p>