title: How to use `regex` to trim a parsed String?
body: <p>I could have used <code>Decimal Format</code>, but I must use <code>regex</code> in this case.
  I have the following String myString = "0.44587628865979384"; I need to trim it to three decimal places, so that is looks like 0.445</p>
  
  <p>I tried the following:</p>
  
  <pre><code>String myString = "0.44587628865979384";
  String newString = myString.replaceFirst("(^0$.)(\\d{3})(\\d+)","$1$2");
  // But this does not work. What is the problem in here?
  </code></pre>