Every object in C++ has access to its own address through an important pointer called this pointer.

The this pointer is an implicit parameter to all member functions.

Therefore, inside a member function, this may be used to refer to the invoking object.

 

Friend functions do not have a this pointer, because friends are not members of a class.

Only member functions have a this pointer.

Let us try the following example to understand the concept of this pointer −

#include 
    
      using namespace std; class Box { public: // Constructor definition Box(double l = 2.0, double b = 2.0, double h = 2.0) { cout <<"Constructor called." << endl; length = l; breadth = b; height = h; } double Volume() { return length * breadth * height; } int compare(Box box) { return this->Volume() > box.Volume(); } private: double length; // Length of a box double breadth; // Breadth of a box double height; // Height of a box }; int main(void) { Box Box1(3.3, 1.2, 1.5); // Declare box1 Box Box2(8.5, 6.0, 2.0); // Declare box2 if(Box1.compare(Box2)) { cout << "Box2 is smaller than Box1" <