title: regexp to check if input is only whole numbers (int) , and to check if another is only numbers with 2 decimal places
body: <p>I want to know what a regex would look like for:</p>
  
  <ol>
  <li>only whole numbers </li>
  <li>only numbers with less than or equal to two decimal places (23, 23.3, 23.43) </li>
  </ol>