namespace Lesson23_面向对象相关_String练习
{
    internal class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("string练习题");
            #region 练习题一
            //请写出string中提供的截取和替换对应的函数名
            string str = "123";
            str = str.Substring(1);
            str = str.Substring(1, 1);

            str = "123123";
            str = str.Replace("123", "哈哈哈");
            #endregion

            #region 练习题二
            string str1 = "1|2|3|4|5|6|7";
            string[] strs = str1.Split('|');
            str1 = "";
            for (int i = 0; i < strs.Length; i++)
            {
                str1 += int.Parse(strs[i]) + 1;
                if(i < strs.Length - 1)
                {
                    str1 += "|";
                }
            }
            Console.WriteLine(str1);
            #endregion

            #region 练习题四
            string strr = null;//开了栈内存1，没开堆内存0
            strr = "123";//堆内存+1
            string str2 = strr;//栈内存+1
            str2 = "321";//堆内存+1
            str2 += "123";//堆内存+1
                          // 请问，上面这段代码，分配了多少个新的堆空间
                          //3个
            #endregion

            #region 练习题五
            //编写一个函数，将输入的字符串反转。不要使用中间商，你必须原地修改输入数组。交换过程中不使用额外空间
            //比如：输入{'h','e','l','l','o'}
            //输出    {'o','l','l','e','h'}

            Console.WriteLine("请输入内容");
            string str3 = Console.ReadLine();
            char[] chars = str3.ToCharArray();
            for (int i = 0; i < chars.Length / 2; i++)
            {
                //交换
                //char temp = chars[i];
                //chars[i] = chars[chars.Length - 1 - i];
                //chars[chars.Length - 1 - i] = temp;
                chars[i] = (char)(chars[i] + chars[chars.Length - 1 - i]);
                chars[chars.Length - 1 - i] = (char)(chars[i] - chars[chars.Length - 1 - i]);
                chars[i] = (char)(chars[i] - chars[chars.Length - 1 - i]);
            }

            for (int i = 0; i < chars.Length; i++)
            {
                Console.Write(chars[i]);
            }

            str3 = new string(chars);
            Console.WriteLine(str3);
            #endregion
        }
    }
}