title: How to check if string has at least one letter, number and special character in php
body: <p>I am currently writing a small script that checks the contents of each string.</p>
  
  <p>I was wondering what the REGEX would be to make sure that a string has a letter (upper or lower), a digit, and a special character?</p>
  
  <p>Here is what I know so far (whcih isn't much):</p>
  
  <pre><code>if(preg_match('/^[a-zA-Z0-9]+$/i', $string)):
  </code></pre>
  
  <p>Help would be great!</p>
  
  <p>Thank You!</p>