Thread: Project Layout

Hi, can you guys tell me if this is the right way to write or layout the codes? It's just a simple project and I finally got it to work. I just don't know if this is the right way to lay things out...

Code:

//SIMPLE CALCULATOR

//In main.cpp

#include <cstdlib>
#include <iostream>
#include "header2.h"
using namespace std;

int main(int argc, char *argv[])
{
    int choice;
    cout << "Please select an option from the menu:\n\n";
    cout << "1. Add\n";
    cout << "2. Subtract\n";
    cout << "3. Multiply\n";
    cout << "4. Divide\n";
    cout << "\nEnter choice:  ";
    cin >> choice;
    cout << "\n\n\n\n";
    switch(choice)
    {
                  case 1:  myFunc();
                       break;
                  case 2:  myFunc2();
                       break;
                  case 3:  myFunc3();
                       break;
                  case 4:  myFunc4();
                       break;
                  default:  cout << "Please select one of the options in the menu.\n";
                            break;
                  }    
    cout << "\n\n\n\n";
    system("PAUSE");
    return EXIT_SUCCESS;
}


//In header2.h
//This is where I list my functions

#include <cstdlib>
#include <iostream>

int myFunc();
int myFunc2();
int myFunc3();
int myFunc4();



//In header1.h
//The class

#include <cstdlib>
#include <iostream>

using namespace std;

class Add
{
      public:
             int getAnswer() const {return one + two;}
             void setAnswer(int a, int b) {one = a, two = b;}
                       
      private:
              int one;
              int two;
      };    
     
class Subtract
{
     public:
             int getsubAnswer() const {return subone - subtwo;}
             void setsubAnswer(int a, int b) {subone = a, subtwo = b;}
                       
      private:
              int subone;
              int subtwo; 
      };

class Multiply
{
     public:
             int getmultAnswer() const {return multone * multtwo;}
             void setmultAnswer(int a, int b) {multone = a, multtwo = b;}
                       
      private:
              int multone;
              int multtwo; 
      };

class Divide
{
     public:
             int getdivAnswer() const {return divtone / divtwo;}
             void setdivAnswer(int a, int b) {divtone = a, divtwo = b;}
                       
      private:
              int divtone;
              int divtwo; 
      };



//In myFunc.cpp
//for addition

#include <cstdlib>
#include <iostream>
#include "header1.h"
using namespace std;

int myFunc()
{
    int numbOne, numbTwo;
    
    cout << "Enter a number:  ";
    cin >> numbOne;
    cout << "Enter another number:  ";
    cin >> numbTwo;
    
    Add myAdd;
    myAdd.setAnswer(numbOne, numbTwo);
    cout << "Answer:  " << myAdd.getAnswer() << "\n\n"; 
    
    return 0;
    }



//In myFunc2.cpp
//For subtraction

#include <cstdlib>
#include <iostream>
#include "header1.h"
using namespace std;

int myFunc2()
{
    int numbOne, numbTwo;
    
    cout << "Enter a number:  ";
    cin >> numbOne;
    cout << "Enter another number:  ";
    cin >> numbTwo;
    
    Subtract mySubtract;
    mySubtract.setsubAnswer(numbOne, numbTwo);
    cout << "Answer:  " << mySubtract.getsubAnswer() << "\n\n"; 
    
    return 0;
    }



//In myFunc3.cpp
//For multiplication

#include <cstdlib>
#include <iostream>
#include "header1.h"
using namespace std;

int myFunc3()
{
    int numbOne, numbTwo;
    
    cout << "Enter a number:  ";
    cin >> numbOne;
    cout << "Enter another number:  ";
    cin >> numbTwo;
    
    Multiply myMultiply;
    myMultiply.setmultAnswer(numbOne, numbTwo);
    cout << "Answer:  " << myMultiply.getmultAnswer() << "\n\n"; 
    
    return 0;
    }



//In myFunc4.cpp
//For division
//here I forgot to set the variables as float - i'll do different next time

#include <cstdlib>
#include <iostream>
#include "header1.h"
using namespace std;

int myFunc4()
{
    int numbOne, numbTwo;
    
    cout << "Enter a number:  ";
    cin >> numbOne;
    cout << "Enter another number:  ";
    cin >> numbTwo;
    
    Divide myDivide;
    myDivide.setdivAnswer(numbOne, numbTwo);
    cout << "Answer:  " << myDivide.getdivAnswer() << "\n\n"; 
    
    return 0;
    }

I set these codes on separate files and linked them.

Is this how I should be laying out the codes? And if you find anything to correct, I'd really appreciate it. Thanks!

That method seems fine. I might put all the function implementations into a single cpp file instead of separating them.

You will want to add header include guards to all of your header files, though.

Also, since your functions do not use the return value, I would make them specify void instead of int as the return type and remove the return statements.

Thanks! That really helped. =)

Good point. Given the way the classes are being used, I think that only providing a two argument constructor and no default constructor might be more appropriate.

>> I don't think I fully understand what the Constructor and Destructor is for.
When I mentioned in the other thread that constructors are important even for beginners' classes, this is a good example of what I was talking about. If you or somebody else is using your classes, and you forget to call setAnswer, then the code will compiler but you will get garbage results.

Maybe it's because I'm coming from java but I din't like that way. I would use main.cpp for main routine and global functions and than per class one <classname>.h file declaring that class with privat and public members and one <classname>.cpp file with the implementation (skipped in your case because all methods are inline). I guess with that source navigation is much easier in bigger projects.