title: Why does NumberStyles.AllowThousands work for int.Parse but not for double.Parse in this example?
body: <p>To parse a string representing a number, with a comma separating thousand digits from the rest, I tried</p>
  <pre><code>int tmp1 = int.Parse(&quot;1,234&quot;, NumberStyles.AllowThousands);
  double tmp2 = double.Parse(&quot;1,000.01&quot;, NumberStyles.AllowThousands);
  </code></pre>
  <p>The first statement is executed without issues, while the second fails with an exception:</p>
  <blockquote>
  <p>An unhandled exception of type 'System.FormatException' occurred in
  mscorlib.dll</p>
  <p>Additional information: Input string was not in a correct format.</p>
  </blockquote>
  <p>Why do not both succeed?</p>