C#字符串反转

A。方法一

  string str = "abcdefg";            

ArrayList arr = new ArrayList();          

   for (int i = 0; i < str.Length; i++)        

     {                 arr.Add(str.Substring(i, 1));             }          

   arr.Reverse();               foreach (string ar in arr)           

  {                 Response.Write(ar);             }

 

B方法二

  string str = "abcdefg";              

 char[] cs = str.ToCharArray();            

Array.Reverse(cs);              

string res = new string(cs);             

  Console.WriteLine(res);

C方法三

 string str = "abcdefg";           

  StringBuilder sb = new StringBuilder();            

 char[] cs = str.ToCharArray();            

 for(int i =  cs.Length-1;i > -1;i++)         

    {                 sb.Append(cs[i]);             }  

            string res = sb.ToString();

 

     string str = "abcdefgh";         

    char[] cs = str.ToCharArray();        

     char temp;          

   int len = cs.Length;           

  for (int i = 0; i < cs.Length / 2 ; i++)        

     {                 temp = cs[i];                 cs[i] = cs[len - 1 - i];                 cs[len - 1 - i] = temp;             }       

        string res = new string(cs);             Console.WriteLine(res);