/*C++ program to demonstrate example of Default Constructor or No argument.*/
#include <iostream>
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;
}
Output
Method 1:
Value after initialization :
X: 0
Y: 0
Enter Value of X: 23
Enter Value of Y: 24
Value after User Input :
X: 23
Y: 24
Method 2:
Value after initialization :
X: 0
Y: 0
Default Constructor or No argument program in C++
Output
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