Copy Constructor in C++

Copy Constructor in C++


A copy constructor is a member function which initializes an object using another object of the same  class.
A copy constructor has the following general function prototype:

           classname (const  classname & old_obj)


// Cpp program to demonstrate Copy constructor.

#include<iostream>
using namespace std;
class  point
{
    private:
                     int  x,y;
    public:
                    point()     // default constructor
              {
                      x=0;y=0;
               }
point (int x1, int y1)    // parameterized constructor

{
          x=x1; y=y1;
}

// Copy Constructor

point(const point &p2)
{
          x=p2.x;
          y=p2.y;
}
void showdata()
{
       cout<<x<<" "<<y<<endl;
}
};
int main()
{
   point  p1;
   point  p2(10,15);       // normal constructor called here 
   point  p3(p2);           // copy constructor called here  p3=p2
   p1.showdata();
   p2.showdata();
   p3.showdata();
   return 0;
}

OUTPUT:

0     0
10   15
10   15