title: Regex expression with Validators.pattern for just integer number
body: <p>I am trying to create a validator for only integers (e.g., 60) using Regex. 
  Here how I am trying to do it:</p>
  
  <pre><code>meter: ["", Validators.required, Validators.pattern(/[0-9]/)]
  </code></pre>
  
  <p>It does not work, but I have to say I am not familiar with this technique. 
  Anyone could shed some light on how I could modify this expression to accept just integers? 
  This number is for height, and the height is devided into meters and centimeter.</p>
  
  <p>I have searched, but I could find for decimals and so, somehow, maybe because it is too trivial, for just integers, I cannot find, in fact, I have found yesterday here, but I cannot find the answer anymore I have found, I was looking for another thing.</p>