/*C++ program to demonstrate example of Default Constructor or No argument.*/ #include using namespace std; //Class declaration. class Demo { //Private block to declare data member( X,Y ) of integer type. private: int X; int Y; //Public block of member function to access data members. public: //Declaration of default or no argument constructor to initialize data members. Demo (); //To take input from user. void Input(); //To display output onn screen. void Display(); };//End of class //Definition of constructor. Demo:: Demo() { X = 0; Y = 0; } //Definition of Input() member function. void Demo:: Input() { cout << "Enter Value of X: "; cin >> X; cout << "Enter Value of Y: "; cin >> Y; } //Definition of Display() member function. void Demo:: Display() { cout << endl << "X: " << X; cout << endl << "Y: " << Y << endl; } int main() { Demo d ;//Ctor autometically call when object is created. //Display value of data member. cout << endl <<"Method 1: " << endl; cout << "Value after initialization : " ; d.Display(); d.Input(); cout << "Value after User Input : "; d.Display(); //We can also create object like this. Demo d1 = Demo(); //Display value of data member. cout << endl << "Method 2: " << endl; cout << "Value after initialization : "; d1.Display(); return 0; }