assignment - not clear

[xxvms]

Hi there,

I have an assignment from my tutor and I am not sure I understand it correctly :(
I need some help with clarification (maybe more experienced people will be able to help)

Make a class to hold 2D array. You must start by defining a class:

class Matrix
{
  private:
  double m[2][2];

* use a 4 argument constructor to initialize the arrays m1 and m2. Use a no arguments constructor to initialize the array elements of m3 to 0.

*Include a printOut method in the class so that we can print out any desired matrix like so: m1.printOut();

*Later: overload the + sign to add together the elements individually inside
the o/operator function like so:

temp.m[0][0] = m[0][0] + mat.m[0][0];

I done I think most of the assignment... however I am not clear on
how to create 4 argument constructor. I do appreciate I need 4 variables
I have added this to private: inside class, but that does not make to much sense
at least for me. Array is type double so I can't use create custom type to hold this inside array.

If you could advise what do you think about the code it would be Fab :)


My tutor got very laid back approach usually reply to my email 1h before my class :(

matrix.h
#pragma once
#include <string>
#include <iostream>

class matrix
{
private:
	double m[2][2];
	int employee;
	std::string name;
	std::string surname;
	double rate;

public:
	matrix()
	{
		m[2][2] = { 0 };
	}
	matrix(int employee_, std::string name_, std::string surname_, double rate_) : employee(employee_), name(name_), surname(surname), rate(rate_)
	{}
	void getData(matrix m_);
	void printOut();
	matrix operator + (matrix am) const; // add 2 matrixes
};

matrix.cpp  
#include "matrix.h"
#include <iostream>


void matrix::printOut()
{
	for (int i = 0; i < 2; i++)
	{
		for (int j = 0; j < 2; j++)
		{
			std::cout << m[i][j] << std::endl;
		}
	}
}

matrix matrix::operator+(matrix am) const
{
	matrix temp;
	for (int i = 0; i < 2; i++)
	{
		for (int j = 0; j < 2; j++)
		{
			temp.m[i][j] = m[i][j] + am.m[i][j];
		}
	}

	return temp;
}
void matrix::getData(matrix m_)
{
	std::cout << "Please enter value for arrya" << std::endl;
	for (int i = 0; i < 2; i++)
	{
		for (int j = 0; j < 2; j++)
		{
			std::cout << "Plese provide " << j+1 << " value: ";
			std::cin >> m[i][j];
		}
	}

}

main.cpp
#include <iostream>
#include "matrix.h"
#include <string>


int main()
{
	matrix m1, m2;
	matrix m3;

	//get data from user
	std::cout << "M1 Object: " << std::endl;
	m1.getData(m1);
	std::cout << "M2 Object: " << std::endl;
	m2.getData(m2);


	// funcion to print out
	std::cout << "Prinint object M1: " << std::endl;
	m1.printOut();
	
	std::cout << "Prinint object M2: " << std::endl;
	m2.printOut();

	//Overloading + operator
	std::cout << "adding M3 = M1 + M2 " << std::endl;
	m3 = m1 + m2;

	std::cout << "Prinint object M3: " << std::endl;
	m3.printOut();

	system("pause");
    return 0;
}

thanks very much :)

[jonnin]

Its just this..

matrix(double OO, double Ol, double lO, double ll)
{
m[0][0] = OO;
m[0][1] = Ol;
... etc
+ whatever you need for your other class members.
}

and

matrix m(1,2,3,4); //use constructor.

[xxvms]

Hi Jonnin

thanks for that, I do appreciate :)

I have noticed as well that there was issue with my code and only thanks to your suggestion it was uncovered. I was not initializing an array in default constructor correctly and it had random values. so that was causing later on program to crash!!!

One thing I am not sure sure is relation between

matrix(double OO, double Ol, double lO, double ll)

and
matrix m(1,2,3,4); //use constructor.

Would that be the same as with function and prototype?

I did like this:

matrix.h

matrix(double One, double Two, double Three, double Four) : m{ 1,2,3,4 } 
	{
		m[0][0] = 1;
		m[0][1] = 2;
		m[1][0] = 3;
		m[1][1] = 4;
	}

main.cpp

matrix m1( 1, 2, 3, 4), m2(1, 2, 3, 4);