This Pointer

When working with classes it is often helpful to be able to refer to the current class instance or object. For example, given the following Car class from a previous lesson, the IncrementDistance() method implicitly refers to the current Car instance's distance attribute:

// The Car class
class Car {
  public:
    // Method to print data.
    void PrintCarData() {
        cout << "The distance that the " << color << " car " << number << " has traveled is: " << distance << "\n";
    }

    // Method to increment the distance travelled.
    void IncrementDistance() {
        distance++;
    }

    // Class/object attributes
    string color;
    int distance = 0;
    int number;
};

It is possible to make this explicit in C++ by using the this pointer, which points to the current class instance. Using this can sometimes be helpful to add clarity to more complicated code:

// The Car class
class Car {
  public:
    // Method to print data.
    void PrintCarData() {
        cout << "The distance that the " << this->color << " car " << this->number << " has traveled is: " << this->distance << "\n";
    }

    // Method to increment the distance travelled.
    void IncrementDistance() {
        this->distance++;
    }

    // Class/object attributes
    string color;
    int distance = 0;
    int number;
};

Note: you may see this used in some code in the remainder of the course.