Question

USING C++:

Referring to the header file below named coord2d.h, Implement each of the 8 operator overloads

(operators: <<, [], >, <, two versions of +, two versions of *)

#ifndef COORD2D_H
#define COORD2D_H

#include <iostream>
using namespace std;

//implement a class that keeps track of the coordinates of a point in the X-Y plane
class coord2d
{
        //overload the << operator so that if p is of type "coord2d" then  "cout<<p";
        //will print out (x_coord, y_coord)
        //e.g. if p.x_coord=3.4, p.y_coord=-7 then "cout<<p" it will print out (3.4, -7)
        friend ostream& operator<<(ostream&, const coord2d&);

        //overload the > operator as a friend function so that if  p1 and p2  are of type "coord2d"
        //p1=(a,b), p2=(c,d)
        //then p1>p2  will true if  a>c and b>d.  It will return false otherwise
        //p1, p2 should not change
        friend bool operator>(const coord2d&, const coord2d&);

        //overload the < operator as a friend function so that if  p1 and p2  are of type "coord2d"
        //p1=(a,b), p2=(c,d)
        //then p1<p2  will true if  a<c and b<d.  It will return false otherwise
        //p1, p2 should not change
        friend bool operator<(const coord2d&, const coord2d&);

        //overload the * operator so that if p1 and p2 are of type "coord2d" and k is a double
        //then p1=k*p2 will result in the coordinates of p1 be set to those of p2 multiplied by k
        //p2 should not change
        //e.g., p1=(3,5), p2=(4,-2), k=2 then p1=k*p2 will result in p1=(8,-4) and p2=(4,-2) 
        friend coord2d operator*(double, const coord2d&);

        //overload the + operator so that if p1 and p2 are of type "coord2d" and x is a double
        //then p1=x+p2 will result in the coordinates of p1 be set to adding x to those of p2 
        //p2 should not change
        //e.g., p1=(3,5), p2=(4,-2), x=3 then p1=x+p2 will result in p1=(7,-1) and p2=(4,-2) 
        friend coord2d operator+(double, const coord2d&);


public:
        coord2d(double a = 0, double b = 0) { 
                x_coord = a, y_coord = b; }
        //default constructor: initializes coordinates x_coord and y_coord to a and b respectively.  
        void set(double a, double b) {
                x_coord = a, y_coord = b;}
        //sets the coordinates to (a,b)


        //overload the + operator as a member function so that if p1 and p2 and p3 are of type "coord2d" 
        //then p1=p2+p3 will result in the coordinates of p1 be set to adding coordinates of p3 to those of p2 
        //p2, p3 should not change
        //e.g., p1=(3,5), p2=(4,-2), p3=(10,20) then p1=p2+p3 will result in p1=(14,18), p2=(4,-2), p3=(10,20)
        coord2d operator+(const coord2d&) const;

        //overload the * operator as a member function so that if p1 and p2  are of type "coord2d"
        //p1=(a,b), p2=(c,d)
        //then p1*p2  will return a*c+b*d
        //p1, p2 should not change
        double operator*(const coord2d&) const;

        //overload [] operator so if p is of type "coord2d", then 
        //p[k] will return p_xcoord if k=0, p[k] will return p.y_coord if k=1 
        //and p[k] will display an error message and exit the program for other k's 
        double& operator[](int);

private:
        double x_coord;  //x coordinate
        double y_coord; //y coordinate
};


#endif

Answer 1

// coord2d.h

#ifndef COORD2D_H
#define COORD2D_H

#include <iostream>
using namespace std;

//implement a class that keeps track of the coordinates of a point in the X-Y plane
class coord2d
{
//overload the << operator so that if p is of type "coord2d" then "cout<<p";
//will print out (x_coord, y_coord)
//e.g. if p.x_coord=3.4, p.y_coord=-7 then "cout<<p" it will print out (3.4, -7)
friend ostream& operator<<(ostream&, const coord2d&);

//overload the > operator as a friend function so that if p1 and p2 are of type "coord2d"
//p1=(a,b), p2=(c,d)
//then p1>p2 will true if a>c and b>d. It will return false otherwise
//p1, p2 should not change
friend bool operator>(const coord2d&, const coord2d&);

//overload the < operator as a friend function so that if p1 and p2 are of type "coord2d"
//p1=(a,b), p2=(c,d)
//then p1<p2 will true if a<c and b<d. It will return false otherwise
//p1, p2 should not change
friend bool operator<(const coord2d&, const coord2d&);

//overload the * operator so that if p1 and p2 are of type "coord2d" and k is a double
//then p1=k*p2 will result in the coordinates of p1 be set to those of p2 multiplied by k
//p2 should not change
//e.g., p1=(3,5), p2=(4,-2), k=2 then p1=k*p2 will result in p1=(8,-4) and p2=(4,-2)
friend coord2d operator*(double, const coord2d&);

//overload the + operator so that if p1 and p2 are of type "coord2d" and x is a double
//then p1=x+p2 will result in the coordinates of p1 be set to adding x to those of p2
//p2 should not change
//e.g., p1=(3,5), p2=(4,-2), x=3 then p1=x+p2 will result in p1=(7,-1) and p2=(4,-2)
friend coord2d operator+(double, const coord2d&);

public:
coord2d(double a = 0, double b = 0) {
x_coord = a, y_coord = b; }
//default constructor: initializes coordinates x_coord and y_coord to a and b respectively.
void set(double a, double b) {
x_coord = a, y_coord = b;}
//sets the coordinates to (a,b)

//overload the + operator as a member function so that if p1 and p2 and p3 are of type "coord2d"
//then p1=p2+p3 will result in the coordinates of p1 be set to adding coordinates of p3 to those of p2
//p2, p3 should not change
//e.g., p1=(3,5), p2=(4,-2), p3=(10,20) then p1=p2+p3 will result in p1=(14,18), p2=(4,-2), p3=(10,20)
coord2d operator+(const coord2d&) const;

//overload the * operator as a member function so that if p1 and p2 are of type "coord2d"
//p1=(a,b), p2=(c,d)
//then p1*p2 will return a*c+b*d
//p1, p2 should not change
double operator*(const coord2d&) const;

//overload [] operator so if p is of type "coord2d", then
//p[k] will return p_xcoord if k=0, p[k] will return p.y_coord if k=1
//and p[k] will display an error message and exit the program for other k's
double& operator[](int);

private:
double x_coord; //x coordinate
double y_coord; //y coordinate
};

#endif

// end of coord2d.h

// coord2d.cpp

#include "coord2d.h"
#include <cstdlib>

ostream& operator<<(ostream& out, const coord2d& p)
{
   out<<"("<<p.x_coord<<", "<<p.y_coord<<")";
   return out;
}

bool operator>(const coord2d& p1, const coord2d& p2)
{
   return ((p1.x_coord > p2.x_coord) && (p1.y_coord > p2.y_coord));
}

bool operator<(const coord2d& p1, const coord2d& p2)
{
   return ((p1.x_coord < p2.x_coord) && (p1.y_coord < p2.y_coord));
}

coord2d operator*(double k, const coord2d& p)
{
   return coord2d(k*p.x_coord,k*p.y_coord);
}

coord2d operator+(double k, const coord2d& p)
{
   return coord2d(k+p.x_coord,k+p.y_coord);
}

coord2d coord2d:: operator+(const coord2d& p) const
{
   return coord2d(x_coord+p.x_coord,y_coord+p.y_coord);
}

double coord2d:: operator*(const coord2d& p) const
{
   return((x_coord*p.x_coord)+(y_coord*p.y_coord));
}

double& coord2d:: operator[](int k)
{
   if(k == 0)
       return x_coord;
   else if(k == 1)
       return y_coord;
   else
   {
       cout<<"Error: input can be 0 or 1"<<endl;
       exit(1);
   }
}

//end of coord2d.cpp

// main.cpp

#include <iostream>
#include "coord2d.h"
using namespace std;

int main()
{
   coord2d p1(3.4, 7) , p2(4,-2), p3(3,5);
   cout<<"P1: "<<p1<<endl;
   cout<<"P2: "<<p2<<endl;
   cout<<"P3: "<<p3<<endl;
   if(p1 > p3)
       cout<<p1<<" > "<<p3<<endl;
   else
       cout<<p1<<" not > "<<p3<<endl;

   if(p1 < p2)
       cout<<p1<<" < "<<p2<<endl;
   else
       cout<<p1<<" not < "<<p2<<endl;

   double k = 2;
   p1 = k*p2;
   cout<<k<<"*"<<p2<<" = "<<p1<<endl;

   p1 = k+p2;
   cout<<k<<"+"<<p2<<" = "<<p1<<endl;

   p1 = p2 + p3;
   cout<<p2<<"+"<<p3<<" = "<<p1<<endl;

   double result = p2 * p3;
   cout<<p2<<"*"<<p3<<" = "<<result<<endl;

   cout<<"P1[0] = "<<p1[0]<<" P1[1] = "<<p1[1]<<endl;

   cout<<"p1[2] = "<<p1[2]<<endl;

   return 0;
}

//end of main.cpp

Output: