static void Main(string[] args) { // Wrong Usage! // Person P; // P.Age = 20; // P.FullName = "Ali Reza Alavi"; // P.ShowInfo(); Person P1; P1 = new Person(); P1.Age = 20; P1.FullName = "Ali Reza Alavi"; P1.ShowInfo(); System.Console.WriteLine("\n"); Person P2 = new Person(); P2.Age = 30; P2.FullName = "Sara Ahmadi"; P2.ShowInfo(); System.Console.WriteLine("\n"); Person P3; P3 = P1; P3.ShowInfo(); System.Console.WriteLine("\n"); Person P4 = P2; P4.ShowInfo(); System.Console.WriteLine("\n"); Person P5 = P1; P5.Age = 21; P5.ShowInfo(); P1.ShowInfo(); System.Console.ReadLine(); }