Objects as Function Arguments

Objects as Function Arguments

•  The objects can be explicitly passed as an argument to the function.

•  Note that in this case, we have to write the constructor explicitly. Because when an object is created as an instance of a class then the constructor is invoked.

•  Following is a simple program in which we are passing the objects as parameter and returning the object.

#include<iostream>

using namespace std;

class point

{

private:

int x,y;

public:

point(int a,int b)

{

    x=a;

    y=b;

}

point()

{

    x=0;

    y=0;

}

point add(point px,point py);

void display();

};

point point::add(point px,point py)

{

    point temp;

    temp.x=px.x+py.x;

    temp.y=px.y+py.y;

    return temp;

}

void point::display()

{

    cout<<"x= "<<x<<" y= "<<y;

}

void main()

{

    point p1(10,20);

    point p2(100,200);

    point p3;

    p3=p3.add(p1,p2);   //Passing two objects p1 and p2

     p3.display();

}

Output

x= 110 y= 220

Program Explanation :

• In above program the class named point is created. In this class the two integers  namely x and y represent the coordinates of the point.

• In the main() function, we create the two instances(objects) of the class point ‒ p1 and p2 respectively. When these objects are created then the constructor point(int a,int b) is invoked. Due to which the values (10,20) and (100,200) gets assigned to two points.

•  The function add is for making the addition of co‒ordinates of the points. For that purpose the two objects p1 and p2 are passed as parameters to the function add. This function returns the addition in the third object p3. Hence finally the values x and y of object p3 are displayed using display function.