title: Formatting a string with string.Format("{0:00}"
body: <p>I have just taken over some code and I see this used a lot. It seems to take the integer and create a string looking like "01", "02" etc. </p>
  
  <p>What I am not sure of is the convention used here. Why is the format <code>{0:00}</code> and not <code>{00}</code>?</p>
  
  <pre><code>string.Format("{0:00}", int.Parse(testVal) + 1);
  </code></pre>