How to use Count and Clear() :

class Program
{
       static void Main()
      {
                  ArrayList list = new ArrayList();
                  list.Add(3);
                  list.Add(8);

                  list.Add(10);
                  list.Add(52);

                 Console.WriteLine(list.Count);  // Show number of element in ArrayList and output=4
                 list.Clear();                               // Clear all the elements of ArrayList.

                Console.WriteLine(list.Count);   // Again count the number of element.
                Console.ReadLine();                  // Output = 0
               }
}

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