C/c++:c++ references

C + + references:

First, write a program like this:

#include <iostream>class point{private:    int x, y;public: Point    (int x, int y) {        this->x = x;        This->y = y;    };    int GetX () {        return x;    }    int GetY () {        return y;    }    void Add (point p) {        this->x + = p.x;        This->y + = P.y;    }}; int main () {point    P (1, 1);    P.add (Point (2, 2));    Std::cout << p.getx () << Std::endl;    Std::cout << p.gety () << Std::endl;    return 0;}

Well, let's analyze this procedure, and when we execute the P.add method, we define an object of such a point,

To pass the value to it. And in the Add method we have defined a variable. and passing a value to another variable is the default execution

The process of a memory copy, and that certainly takes time. Of course, the words here are not going to take much time, if your program

Very large, you write like this, it is another matter, and this type of copy is completely unnecessary. and C + + gives us a

Reference (&) This function, of course, we can also use pointers to do ... Using a quote, we just have to change it a little bit.

#include <iostream>class point{private:    int x, y;public: Point    (int x, int y) {        this->x = x;        This->y = y;    };    int GetX () {        return x;    }    int GetY () {        return y;    }    void Add (Point &p) {        this->x + = p.x;        This->y + = P.y;    }}; int main () {point    P (1, 1);    Point A (2, 2);    P.add (a);    P.add (Point (2, 2));    Std::cout << p.getx () << Std::endl;    Std::cout << p.gety () << Std::endl;    return 0;}

This way we also avoid the process of the memory copy.

PS: Come on!

C/c++:c++ references