title: Define range of digit for an already defined pattern in regex
body: <p>As wierd i'm missing something i can't find in SO answers already given</p>
  
  <p>I created a regex to match these requirements :</p>
  
  <ul>
  <li>A string that match any number or these alphanumeric (_,-,whitespace)</li>
  <li>this string must be in range of 3 to 23 chars length.</li>
  </ul>
  
  <p>I made up the regex for match as a start <code>^[a-zA-Z0-9_ -]*$</code> which normally match the first requirement</p>
  
  <p>Now i change the * quantifier match to give a range of digit such as d{3,23} such as the regex would look like</p>
  
  <pre><code>^[a-zA-Z0-9_ -]\d{3,23}$
  </code></pre>
  
  <p>Well, it doesn't matches. Some help would be nice also with some explaination please.</p>