title: Regex for password with minimum 6 characters length
body: <p>I need a regex to validate password with below conditions</p>
  
  <ol>
  <li>At least 6 characters long</li>
  <li>Should contain at least 1 letter </li>
  <li>Should contain at least 1 number</li>
  <li>If the password contains special characters, that should be allowed,  <strong>but  special character is not mandatory</strong>.</li>
  </ol>