intList(ICollection)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Collections;

namespace ConsoleApplication11
{
    class intList : System.Collections.ICollection
    {
        int[] M;
        int count;
        const int defaultCapacity = 0;

        public intList(int cap)
        {
            M = new int[cap];
            count = 0;
        }

       // int System.Collections.ICollection.Count
        //{
        //    get
        //    {
        //        return count;
        //    }
        //}

        public int Count
        {
            get { return count; }
            set { value = count; }
        }

        public int this[int ind]
        {
            get { return M[ind]; }
            set { value = M[ind]; }
        }

        bool System.Collections.ICollection.IsSynchronized
        {
            get
            {
                return false;
            }
        }

        object System.Collections.ICollection.SyncRoot
        {
            get
            {
                return this;
            }
        }

        void System.Collections.ICollection.CopyTo(Array array, int index)
        {
            intList l = new intList(array.Length);
            foreach(int i in M)
            {
                array.SetValue(i, index);
                index++;
            }

        }

        IEnumerator IEnumerable.GetEnumerator()
        {
            for (int i = 0; i < count; i++)
                yield return M[i];
        }

        public int Capacity
        {
            get { return M.Length; }
            set
            {
                if (value < count)
                    value = count;
                if (value != M.Length)
                {
                    int[] nm = new int[value];
                    Array.Copy(M, nm, M.Length);
                    M = nm;
                }
            }
        }

        public void Add(int item)
        {
            if (Capacity == count)
                Capacity = count * 2;
            M[count] = item;
            count++;
        }

        public void AddRange(System.Collections.ICollection ar)
        {
            intList s = (intList)ar;
            foreach(int item in s)
            {
                this.Add(item);
            }
        }

        public void SetRange(int k, System.Collections.ICollection ar)
        {
            intList s = (intList)ar;
            foreach(int item in s)
            {
                if (k == Capacity)
                    Add(item);
                else
                    M[k] = item;
                k++;
            }
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            intList IL = new intList(10);
            IL.Add(1);
            IL.Add(2);
            IL.Add(3);
            intList IL1 = new intList(10);
            IL1.Add(4);
            IL1.Add(5);
            IL.AddRange(IL1);
            IL.SetRange(0, IL1);
            Console.WriteLine("count = {0}", IL.Count);
            Console.WriteLine("Capacity = {0}", IL.Capacity);
            for (int i =0; i < IL.Count; i++)
            {
                Console.Write("{0,5}", IL[i]);
            }
            Console.WriteLine();
            Console.ReadKey();
        }
    }
}