Answer to Question #327661 in C++ for khan

Question

Task:1

A single point has two coordinates p1(x,y). Create a class name Point with a length 2 array asit's private data member. Initialize the array using constructor. Overload array subscript operator ‘[ ]’ for if I have to access the object's array at a particular index from main function

like this.

Point p1(1, 1);

cout << p1[0] << " " << p1[1] << endl;

Task#02:

Copy paste the same task and do consider doing it in dynamic memory instead of static. Plus alter the subscript overloaded function for if I have to make changes to the class array from the main function. Hint: By reference

Point p2(3, 3);

cout << p2[0] << " " << p2[1] << endl;

p2[0] = 7;

p2[1] = 9;

cout << p2[0] << " " << p2[1] << endl;

Answer 1

Task1

#include <iostream>
using namespace std;


class Point {
public:
    Point(double x, double y);
    double& operator[](int i);
    double operator[](int i) const;


private:
    double data[2];
};


Point::Point(double x, double y) {
    data[0] = x;
    data[1] = y;
}
double& Point::operator[](int i) {
    return data[i];
}
double Point::operator[](int i) const
{
    return data[i];
}


int main() {
    Point p1(1, 1);


    cout << p1[0] << ' ' << p1[1] << endl;


    return 0;
}

Task2

#include <iostream>
using namespace std;


class Point {
public:
    Point(double x, double y);
    Point(const Point& p);
    ~Point();
    Point& operator=(const Point& p);
    double& operator[](int i);
    double operator[](int i) const;


private:
    double *data;
};


Point::Point(double x, double y) {
    data = new double[2];
    data[0] = x;
    data[1] = y;
}
Point::Point(const Point& p) {
    data = new double[2];
    data[0] = p.data[0];
    data[1] = p.data[2];
}
Point::~Point() {
    delete [] data;
}
Point& Point::operator=(const Point& p) {
    if (&p == this) {
        return *this;
    }


    delete [] data;
    data = new double[2];
    data[0] = p.data[0];
    data[1] = p.data[2];
    return *this;
}
double& Point::operator[](int i) {
    return data[i];
}
double Point::operator[](int i) const
{
    return data[i];
}


int main() {
    Point p2(3, 3);

    cout << p2[0] << ' ' << p2[1] << endl;
    p2[0] = 7;
    p2[1] = 9;
    cout << p2[0] << ' ' << p2[1] << endl;

    return 0;
}