集合类操作

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

namespace Arraylist
{
    class Program
    {
        static void Main(string[] args)
        {
            ArrayList al = new ArrayList();
            //向集合中添加元素
            al.Add(3000);
            al.Add(4000);
            al.Add(5000);
            al.Add(5000);
            al.Add(5000);
            ////数组的个数
            //Console.WriteLine(al.Count);
            //// 数组的容量
            //Console.WriteLine(al.Capacity);
            //int a = Convert.ToInt32(al[0]);
            //Console.WriteLine(a.ToString());

            //遍历数组
            //计算总工资  for循环
            //int sum = 0;
            //for (int i = 0; i < al.Count; i++)
            //{
            //    int n = Convert.ToInt32(al[i]);
            //    sum += n;
            //}
            //Console.WriteLine(sum);

            //foreach循环
            int sum = 0;
            foreach (object item in al)
            {
                int n = Convert.ToInt32(item);
                sum += n;
            }
            Console.WriteLine(sum);
            Console.Read();
        }
    }
}