creating class, and linking files

Hello Everytone,

I have made this far in this beginning class thanks to all your help.... :) And now I'm having a BIG problem working on my last project...... :confused:
I'm trying to make a cliend code file that will link to a class that contains few functions (specifications), and I also need to make a implementation file for the class. I think I got some general ideas as how specification and implementation work, however, would someone please give me some beginner pointers as how those things work together, such as some skeletal codes.

In addition, I'm using the Microsoft visuall ++ software to create all the files. I read the book that says the integrate environment (such as MS C++) will link all files automatically. However, mine didn't seem to work. I've used #include "class.h" on the heading for the client code and implementation, what else did I miss?

Thanks so much again everyone!! :)

Here is my class code and client code:

Code:

---


//Specification of the class "Applicant"


class Applicant
{
public:
        float Calculate_BasicPremium (string, int, string);
        //calculate the basic premium based on the applicant's gender, age, and coverage type
       
        //Preconditions:
        //valid data are provided, such as the applicant's first and last name, gender,
        //age, type of coverage

        //Postconditions:
        //The basic premium is calculated based on the data provided

        float Discount_Premium (float basic_premium, string club_member, string smoker);
        //discount the basic premium based on the applicant's health status, and smoking
        //status

        //Preconditions:
        //The Calculate_BasicPremium function has been executed, and a valid value has been
        //returned, plus that the applicant's health club and smoking status are known

        //Postconditions:
        //Discount premium is calculated based on the information given above

        float Adjust_Premium (float discount_premium, int zip_code);
        //adjust the premium based on the zip code
       
        //Preconditions:
        //Both Calculate_BasicPremium and Discount_Premium functions have been executed, and
        //the applicant's zip code is provided

        //Postconditions:
        //Applicant's final premium is calculated

        Applicant();                                //Constructor

private:
        string first_name;                                //declare string variable first name
        string last_name;                                //declare string variable last name
        string gender;                                        //declare string variable gender
        int age;                                                //declare int variable age
        string type_coverage;                        //declare string variable type of coverage
        string club_member;                                //declare string variable health club
                                                                        //member
        string smoker;                                        //declare string variable smoker
        int zip_code;                                        //declare int variable zip code
        float basic_premium;                        //declare float variable basic premium
        float discount_premium;                        //declare float variable premium
        float adjust_premium;                        //declare float variable adjust premium
        float premium;                                        //declare float variable variable premium
};

---

Here is the client code:

Code:

---

#include "applicant.h"
#include <iostream>
#include <string>
#include <iomanip>
#include <fstream>


using namespace std;


int main()
{
  string first_name;            //declare string variable first name
  string last_name;            //declare string variable last name
  string gender;                //declare string variable gender
  int age;                      //declare int variable age
  string type_coverage;        //declare string variable type of coverage
  string club_member;          //declare string variable health club
                                //member
  string smoker;                //declare string variable smoker
  int zip_code;                //declare int variable zip code
  float basic_premium;                        //declare float variable basic premium
  float discount_premium;                //declare float variable premium
  float adjust_premium;                        //declare float variable adjust premium
  float premium;                                //declare float variable variable premium
  ifstream inFile;              //declare file streams
  ofstream outFile;

  inFile.open("C:\\Windows\\C++\\project5\\proj5.in.txt");      //opens the input file
  outFile.open("C:\\Windows\\C++\\project5\\proj5.out.txt");    //opens the output file

  if (!inFile)
  {
    cout << "Input file failed!" << endl;
    return 1;                  //terminates the program if input fails
  }   

  inFile >> first_name >> last_name >> gender >> age >> type_coverage >>
  club_member >> smoker >> zip_code;    //assigns input values from inFile

  //prints subject line
  outFile << "===================================" << endl; 
  outFile << "          PREMIUM QUOTES          " << endl;
  outFile << "===================================" << endl;

  outFile << "Name" << "\t" << "\t" << "Coverage Type" << "\t" << "Zip" <<
  "\t" << "Premium" << endl << endl;    //prints headline                             

  while (inFile)                        //looping in capturing &
                                        //processing input data
  {
          basic_premium = Applicant.Calculate_BasicPremium (gender, age, type_coverage);
          discount_premium = Applicant.Discount_Premium (basic_premium, club_member, smoker);
          premium = Applicant.Adjust_Premium (discount_premium, zip_code);

          outFile << first_name << "\t" << last_name << "\t" << type_coverage
      << "\t" << "\t" << zip_code << "\t" << "$" << premium << endl;
      //output premium to file output                                   

      inFile >> first_name >> last_name >> gender >> age >> type_coverage >>
      club_member >> smoker >> zip_code;  //assigns input values to inFile
  }

  if(!outFile)
  {
    cout << "Output file failed!" << endl;
    return 1;                  //terminates the program if output fials
  }
  return 0;
}

---

Well, what errors are you getting?
I noticed that you include Applicant.h before string.h, meaning the compiler can't recognice strings in your class declaration.

Ah....HA! yes, I'm getting a whole bunch of errors about syntax error..... that's why.... it is funny my teacher didn't talk anything about that and the book also didn't mention it....

but what is string.h?

Thanks so much!! :)

here is just a small sampling of all the errors I got from compiling the client code.....

c:\windows\c++\project5\applicant.h(17) : error C2061: syntax error : identifier 'string'
cerror : missing ';' before identifier 'first_name'
c:\windows\c++\project5\applicant.h(51) : error C2501: 'string' : missing storage-class or type specifiers

Change this

Code:

---

#include "applicant.h"
#include <iostream>
#include <string>
#include <iomanip>
#include <fstream>

---

Into this

Code:

---

#include <iostream>
#include <string>
#include <iomanip>
#include <fstream>
#include "applicant.h"

---

and see if it works better.

Magos,

Thanks so much for the help!! I changed the headings but it still gave me the same errors....
do you think it could the capitalization problem?? I use "applicant.h" as the file name, however, when I declared the class, I used "Applicant"... and everywhere else....

:confused:

What did you save applicant as? it is case sensative.

No, capitalization doesn't matter when including files, only when declaring variables.

<edit>This reply was pointed at JCK :)</edit>

I never see you use the class anywhere. I don't think it should matter though, since it seems like the compiler doesn't recoginze the string datatype.

<edit2>And why do you create all those variables again in main? You don't think you have an error in your planning?</edit2>

I used the class in the while loop in the main function.....
the class then calls another file "applicant.cpp" which contains the details of the function. I didn't post it because it is too long.....
Do you think perhaps there is problem in that file?

I erased all the variables in the main function, but still getting error that say "syntax error, idendifier string"...

I used the class in the while loop in the main function.....
the class then calls another file "applicant.cpp" which contains the details of the function. I didn't post it because it is too long.....
Do you think perhaps there is problem in that file?

I erased all the variables in the main function, but still getting error that say "syntax error, idendifier string"...

Quote:

---

class Applicant
{
...
};

basic_premium = Applicant.Calculate_BasicPremium (gender, age, type_coverage);

---

You can't call the methods directly from the class (unless they're static). You have to create an instance first.

Code:

---

myclass.h

class MYCLASS
{
  public:
      void MyMethod();
};

---

Code:

---

myclass.cpp

MYCLASS::MyMethod()
{
  ...
}

---

Code:

---

myapplication.cpp

int main()
{
  MYCLASS MyClass;

  MyClass.MyMethod();
}

---

Thanks so much Magos, although I'm still a little confused..... :confused:
so, what's a constructor then.... ?

Quote:

---

Originally posted by JCK
Thanks so much Magos, although I'm still a little confused..... :confused:
so, what's a constructor then.... ?

---

A piece of code that is run when the object is created.