字符和字符串的关系：字符串可以看成是只读字符数组

using System;namespace ConsoleApplication2{    class Program    {        /**         * 字符和字符串的关系：字符串可以看成是只读字符数组         */        static void Main(string[] args)        {            char c = 'a';            char c2 = '中';            // char c3 = 'fdf'; error            // char c4 = '';    error            string s = "a";            string s2 = "";            string s3 = "fdf";            string s4 = "我是中国人";            char s5 = s4[0];            Console.WriteLine(s5);            // s4[0] = '你'; error.他是只读的            Console.WriteLine("------------------------------");            foreach(char s44 in s4)            {                Console.WriteLine(s44);            }            Console.WriteLine("------------------------------");            for (int i = s4.Length - 1; i >= 0; i -- )            {                Console.WriteLine(s4[i]);            }            Console.ReadKey();        }    }}