title: Clear all array list data
body: <p>Why doesn't the code below clear all array list data?</p>
  
  <pre><code>        Console.WriteLine("Before cleaning:" + Convert.ToString(ID.Count));
          //ID.Count = 20
          for (int i = 0; i &lt; ID.Count; i++)
          {
              ID.RemoveAt(i);
          }
          Console.WriteLine("After cleaning:" + Convert.ToString(ID.Count));
          //ID.Count = 10
  </code></pre>
  
  <p>Why is 10 printed to the screen?</p>
  
  <p>Maybe there is another special function, which deletes everything? </p>