title: RegEx to make sure that the string contains at least one lower case char, upper case char, digit and symbol
body: <p>What is the regex to make sure that a given string contains at least one character from each of the following categories. </p>
  
  <ul>
  <li>Lowercase character</li>
  <li>Uppercase character</li>
  <li>Digit </li>
  <li>Symbol</li>
  </ul>
  
  <p>I know the patterns for individual sets namely <code>[a-z]</code>, <code>[A-Z]</code>, <code>\d</code> and <code>_|[^\w]</code> (I got them correct, didn't I?). </p>
  
  <p>But how do I combine them to make sure that the string contains all of these in any order?</p>