重载函数

class Program
    {
        static void Main(string[] args)
        {
            Example emp = new Example();
            string result = emp.sell();
            Console.WriteLine("原样输出-----" + result);
            result = emp.sell(": ");
            Console.WriteLine("插入字符串--" + result);
            result = emp.sell(20000);
            Console.WriteLine("格式化文本--" + result);
            Console.Read();

        }
    }
    class Example
    {
        private string tmpstr="销售额";
        /// <summary>
        /// 输出字符串
        /// </summary>
        /// <returns></returns>
        public string  sell()
        {
            return tmpstr;
            
        }
        /// <summary>
        /// 在字符串的结尾插入给定的字符串
        /// </summary>
        /// <param name="s"></param>
        /// <returns></returns>
        public string sell(string s) 
        {
            return tmpstr.Insert(tmpstr.Length, s);
        }
        /// <summary>
        /// 格式化字符串
        /// </summary>
        /// <param name="num"></param>
        /// <returns></returns>
        public string sell(int num) 
        {
            StringBuilder sb = new StringBuilder(tmpstr);
            sb.AppendFormat("{0:C}", num);
            return sb.ToString();

        }
    }

class Program
    {
        static void Main(string[] args)
        {
            Example emp = new Example();
            string result = emp.sell();
            Console.WriteLine("原样输出-----" + result);
            result = emp.sell(": ");
            Console.WriteLine("插入字符串--" + result);
            result = emp.sell(20000);
            Console.WriteLine("格式化文本--" + result);
            Console.Read();

        }
    }
    class Example
    {
        private string tmpstr="销售额";
        /// <summary>
        /// 输出字符串
        /// </summary>
        /// <returns></returns>
        public string  sell()
        {
            return tmpstr;
            
        }
        /// <summary>
        /// 在字符串的结尾插入给定的字符串
        /// </summary>
        /// <param name="s"></param>
        /// <returns></returns>
        public string sell(string s) 
        {
            return tmpstr.Insert(tmpstr.Length, s);
        }
        /// <summary>
        /// 格式化字符串
        /// </summary>
        /// <param name="num"></param>
        /// <returns></returns>
        public string sell(int num) 
        {
            StringBuilder sb = new StringBuilder(tmpstr);
            sb.AppendFormat("{0:C}", num);
            return sb.ToString();

        }
    }