非泛型集合ArrayList：

using System;
using System.Collections.Generic;//泛型
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Collections;//非泛型

namespace demo
{
    class example_05
    {
        static void Main()
        {
            ArrayList array = new ArrayList();
            array.Add(100);
            array.Add(86);
            int position = array.Add(77);
            Console.WriteLine(position);//2 

            int total = 0;//和
            double average = 0.0;//平均值

           foreach (int item in array)
            {
                total += item;
            }

            average = total / array.Count;

            Console.WriteLine(total);
            Console.WriteLine(average);

            array.Insert(1, 99);//早索引为1的地方插入99
            array.Insert(3,80);

            Console.WriteLine(array.Count);//元素数量 5
            Console.WriteLine(array.Capacity);// 8
            array.Insert(1, 99);
            array.Insert(3, 80);
            array.Insert(1, 99);
            array.Insert(3, 80);

            Console.WriteLine(array.Count);//元素数量  9
            Console.WriteLine(array.Capacity);//数组默认容器大小，如果大于8时，自动扩充到16.

           if (array.Contains(54))//检查是否包含
           {
               array.Remove(54);//移除元素
           }
            else
            {
                Console.WriteLine("没有54");
            }

            array.RemoveAt(4);//移除索引处的元素
            Console.WriteLine(array.Count);

            array.Add(70);
           int pos = array.IndexOf(70);//查找元素的索引位置
           Console.WriteLine("pos:"+pos);
}
}
}

 ArrayList names = new ArrayList();
            names.Add("zhandsan");
            names.Add("钱琪");
            names.Add("zhaoliu");

            foreach (Object name in names)
            {
                Console.WriteLine(name);
            }
            Console.WriteLine();

            String[] newNames = new String[] { "qwe", "dsd" };
            ArrayList moreNames = new ArrayList();
            moreNames.Add("刘晓丽");
            moreNames.Add("临海");
            moreNames.Add("例如");

            names.InsertRange(0, newNames);//插入多个
            names.AddRange(moreNames);//多个加到末尾
            Console.WriteLine("添加了6个元素以后的内容");
            foreach (Object name in names)
            {
                Console.WriteLine(name);
            }
            ArrayList someName = new ArrayList();
            someName = names.GetRange(2, 3);//获取索引2开始的3个元素
            foreach (Object name in someName)
            {
                Console.WriteLine(name);
            }
            names.Clear();//清空