C#字符串操作

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

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            String strS = "This Is An Apple.";
            for (int i = strS.Length-1; i >= 0; i--)
            {
                Console.Write(strS[i]);
            }
            Console.WriteLine();
            String[] ch = strS.Split('A');
            Console.WriteLine("字符串A出现了{0}次。", ch.Length-1);
            String[] ch1 = strS.Split(' ');
            Console.WriteLine("字符串单词有{0}个。", ch1.Length );
            Console.WriteLine("字符串全部转换成大写为：",strS.ToUpper());
            Console.ReadKey();
        }
    }
}