title: PHP Allow only numbers with 2 decimals
body: <p>I need a function to check if number have 2 decimals or not.</p>
  
  <p>For example:</p>
  
  <pre><code>$number = '1.00'; // Valid
  $number2 = '1'; // Not valid
  $number3 = '1.000' //Not valid
  </code></pre>