Question

12.24 HW2: Practice with Classes

Objectives:

• Become familiar with developing a C++ class, to include developing:
  • A constructor
  • An multiplication operator
  • A friend function (input operator)
• Introduce various C and C++ functions for parsing user input

Assignment Details

This assignment consists of 6 parts.

Part 1: Using an IDE of your own choosing (Visual Studio is recommended), create a new project and copy the starter code

• ComplexNumber.h
• ComplexNumber.cpp and
• TestComplexNumber.cpp

to this new project for developing and testing your solution.

Part 2: Complete the specification in ComplexNumber.h by adding function prototypes for:

• A ComplexNumber constructor which takes as a parameter a single C-sytle string (i.e., const char *)

• A multiplication operator as a member function which takes as a parameter a single constant reference to a ComplexNumber and returns a ComplexNumber

• An input operator as a friend function which takes two input parameters

  • A reference to an istream and
  • A reference to a ComplexNumber and

  Initializes the ComplexNumber to value given in the istream and returns the modified istream

Part 3: Write implementations for the three new functions specified in Part 2. Your functions should adhere to the following requirements:

• Your constructor initializes a ComplexNumber object using a C-string with one of the following forms:
  1. [+|-]realNumber
  2. [+|-][realNumber]i
  3. [+|-]realNumber(+|-)[realNumber]i
  • Please note:
    • | stands for OR,
    • [] stands for OPTIONALLY,
    • () stands for EITHER, and
    • realNumber stands for any valid real number literal, including numbers in signed or unsigned scientific notation.
  • For full credit your constructor must be able to read complex numbers matching any of the three forms.
  • For simplicity, your solution is not required to reject ill-formed complex numbers (i.e., numbers which do not match the specification above)
• Your multiplication operator must be a member function using * as the operator and correctly multiply the this object and the ComplexNumber parameter and return the resulting ComplexNumber according to the definition for ComplexNumber multiplication from Wolfram.
• Your input operator must be a friend function using >> as the operator and allow initialization of the ComplexNumber parameter using the input stream (e.g., typically cin).

These three functions are the only new functions you are required to add to ComplexNumber.cpp. While it is not necessary, you may add as many additional non-member or non-friend functions as you want to complete your solution.

Part 4: Test your implementations from Parts 2 and 3 using TestComplexNumber.cpp and various valid complex numbers.

Example Inputs and Results:

     
      Testing the string constructor with "1.23e-1+4.5i" results in the value 0.123+4.5i
     

Answer 1

The contents of the file "ComplexNumber.h" is given below:-

//----------------------------------------------------------------------------------------------------------------

/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/

/*
* File: ComplexNumber.h
* Author: vipul
*
* Created on 29 January, 2020, 8:14 PM
*/

#ifndef COMPLEXNUMBER_H
#define COMPLEXNUMBER_H

#include <iostream>

using namespace std;

class ComplexNumber {
public:
ComplexNumber();
ComplexNumber(const char * str);
ComplexNumber(const ComplexNumber& orig);
ComplexNumber operator*(const ComplexNumber& c);
friend istream& operator>>(istream& din,ComplexNumber& c);
private:
double real,img;
};

#endif /* COMPLEXNUMBER_H */

//--------------------------------------------------------------------------------------

The contents of the file "ComplexNumber.cpp" are given below:-

//-------------------------------------------------------------------------------------------------

/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/

/*
* File: ComplexNumber.cpp
* Author: vipul
*
* Created on 29 January, 2020, 8:14 PM
*/

#include <iostream>
#include <string.h>
#include <math.h>

#include "ComplexNumber.h"

using namespace std;

ComplexNumber::ComplexNumber() {
this->real = 0;
this->img = 0;
}

ComplexNumber::ComplexNumber(const char * str) {
  
double x,y;
char i;
if (std::cin>>x >>y>>i && i=='i')
{
this->real = x;
this->img = y;
}
else
{
std::cout<< "Invalid String!"<<endl;
exit(1);
}
}

ComplexNumber::ComplexNumber(const ComplexNumber& orig) {
this->real = orig.real;
this->img = orig.img;
}

ComplexNumber ComplexNumber::operator*(const ComplexNumber& c)
{
ComplexNumber temp;
temp.real = (this->real)*(c.real) - (this->img)*(c.img);
temp.img = (this->real)*(c.img) + (this->img)*(c.real);
return temp;
}

istream& operator>>(istream& din,ComplexNumber& c)
{
din>>c.real;
din>>c.img;
return din;
}

//-------------------------------------------------------------------------------------------------

The contents of the file "TestComplexNumber.cpp" are given below:-

//----------------------------------------------------------------------------------------------------

/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/

/*
* File: main.cpp
* Author: vipul
*
* Created on 29 January, 2020, 8:12 PM
*/

#include <iostream>
#include <cstdlib>

#include "ComplexNumber.h"

using namespace std;

/*
*
*/
int main(int argc, char** argv) {
cout<<"Hello!"<<endl;
ComplexNumber c1("-10+15i");
  
return 0;
}

//----------------------------------------------------------------------------------------------------