String常见属性方法

1.String.Join

   string[] s = { "我", "爱", "中","国" };
                string s1=String.Join(" ",s);
                Console.WriteLine(s1); //输出：我 爱 中 国
                Console.WriteLine(s1.Length);//长度为7

2.将字符数组转为字符串

  char[] letters = new char[] { 'a','b','c' };
                string str = new  string(letters); ////通过使用 string 构造函数
                Console.WriteLine(str);//输出 abc

 将字符串转为字符数组

   string s5 = "gbd";
                char [] array=s5.ToCharArray();
                Console.WriteLine(array[0]);

3.String.Fomat

    DateTime dateTime = new DateTime(2020,07,31,14,12,20);
                string aa = string.Format("{0:t} {0:d}", dateTime);
                Console.WriteLine(aa);//输出 14:12 2020/7/31

 4.String.Split('','')

     string str1 = "abc,123,ABC" ;
                string[] a0 = s1.Split(',',';');