static void Main(string[] args) { Console.WriteLine("Hello World!"); //create a Hello World program in C# //Reference type Triangle triangle = new Triangle(); triangle.a = 4; triangle.b = 4; triangle.c = 6; Console.WriteLine("First triangle perimeter: " + Triangle.perimeter(triangle.a, triangle.b, triangle.c)); Triangle.Display(triangle.c); Triangle.numberOfObjects(); Triangle triangle1 = new Triangle(); triangle1.b = 5; Console.WriteLine("Second triangle perimeter: " + Triangle.perimeter(triangle1.a, triangle1.b, triangle1.c)); Triangle.Display(triangle1.c); //display the number of objects create-->using a static method Triangle.numberOfObjects(); Console.WriteLine("Number of objects: " + Triangle.count); //use of boxing and unboxing int number = Triangle.count; object obj = number; //boxing Console.WriteLine(obj); int number2 = (int)obj; //unboxing Console.WriteLine(number2); Console.WriteLine(triangle.a + " " + triangle.b + " " + triangle.c); Console.WriteLine(triangle1.a + " " + triangle1.b + " " + triangle1.c); //Value type Console.WriteLine(""); Console.WriteLine("Value type"); rightAngle rightAngle = new rightAngle(); rightAngle.l = 2; rightAngle.L = 5; rightAngle rightAngle1 = new rightAngle(); rightAngle1.l = 3; Console.WriteLine(rightAngle.l + " " + rightAngle.L); Console.WriteLine(rightAngle1.l + " " + rightAngle1.L); //ref modifier int x = 3; Adder(ref x); Console.WriteLine("x after the function call with ref value: " + x); //out modifier int y = 9; Adder2(out y); Console.WriteLine("y after the function call with out value: " + y); Console.ReadKey(); }