C# 7.0 新增功能&结合微软简化理解

                string str = "123";
                int result;
                int.TryParse(str, out  result);
                result += 1;
                Console.WriteLine("result + 1 =？ {0}", result.ToString());

                string str = "123";
                int.TryParse(str, out int result);
                result += 1;
                Console.WriteLine("result + 1 =？ {0}", result.ToString());