title: How do you remove all the alphabetic characters from a string?
body: <p>I have a string containg alphabetic characters, for example:</p>
  
  <ol>
  <li><strong>254.69 meters</strong></li>
  <li><strong>26.56 cm</strong></li>
  <li><strong>23.36 inches</strong></li>
  <li><strong>100.85 ft</strong></li>
  </ol>
  
  <p>I want to remove all the alphabetic characters (units) from the above mentioned strings so that I can call the <code>double.Parse()</code> method.</p>