46new_delete_this.cpp

#include <iostream>
using namespace std;

class A
{
    int a;

public:
    void setData(int a)
    {
        this->a = a;
    }
    void getData()
    {
        cout << " Value of a is " << a << endl;
    }
};

int main()
{
    //"new" keyyword / operator for pointers

    float *p1 = new float(45.23);
    cout << "Value of p1 is " << *(p1) << endl;

    int *p2 = new int(7);
    cout << "Value of p2 is " << *(p2) << endl;

    int *arr = new int[3];
    arr[0] = 10;
    *(arr + 1) = 20;
    arr[2] = 30;
    cout << "Value of arr[0] is " << arr[0] << endl;
    cout << "Value of arr[1] is " << *(arr + 1) << endl;
    cout << "Value of arr[2] is " << arr[2] << endl;

    //"delete" keyword / operator

    delete arr; // to free the pointer memory
    cout << "Value of arr[0] is " << arr[0] << endl;
    cout << "Value of arr[1] is " << *(arr + 1) << endl;
    cout << "Value of arr[2] is " << arr[2] << endl;

    delete[] arr; // to delete enitre block of array
    cout << "Value of arr[0] is " << arr[0] << endl;
    cout << "Value of arr[1] is " << *(arr + 1) << endl;
    cout << "Value of arr[2] is " << arr[2] << endl;

    // "this" keyword / pointer
    A a;
    a.setData(4);
    a.getData();
    /*
    "this" is a keyword which is a pointer which points to the object that invokes the class member
    It's other use is to return the object in the member function if there is a need for it
        it is required for this since there is no object before the function
    */
    return 0;
}