title: RegEx that matches positive numbers
body: <p>I need to write a regex to allow only positive number ( integers or decimals). I have found this: </p>
  
  <pre><code>/^(?!(?:0|0\.0|0\.00)$)[+]?\d+(\.\d|\.\d[0-9])?$/  
  </code></pre>
  
  <p>but it just accepts up to 2 decimal places. What changes do I have to make, so that it can accept any  number of decimal places?</p>
  
  <p>Also where can I find a good tutorial for learning regex.</p>
  
  <p>Thanks beforehand</p>