[RESOLVED] Unresolved external symbol

[crisdeveloper]

i can´t understand this message

this is the central problem

'one or more multiply defined symbols found'

[crisdeveloper]

the problem now is:

one or more multiply defined symbols found!

[GCDEF]

i forget to put namespace std, then i fix the error with 'cout´s'. i also should to put stdafx.h in Person.h? or not?

stdafx.h should be the first #include in your .cpp files.

[GCDEF]

the problem now is:

one or more multiply defined symbols found!

Calm down. You've posted that three times in five minutes. You'll likely get help, but it's not usually going to be instant.

[Paul McKenzie]

i forget to put namespace std,

Where did you place the "using namespace std"? Hopefully it is not in the header file Person.h.

Second, your Person.h is wrong. The only thing in there is supposed to be the class definition and any functions that are inline with the class -- nothing else.

#ifndef PERSON_H
#define PERSON_H

#include <string>
class Person
{    
    public:
	Person();
            ~Person();
	//Accessor Methods
	std::string getName ()  const { return Name; }
	std::string getLocation ()const { return Location; }
	std::string getAge () const { return Age; }
	std::string getOccupation () const { return Occupation; }

	void setName       (const std::string& Name)       { this->Name = Name; }
	void setLocation   (const std::string& Location)   { this->Location = Location; }
	void setAge        (const std::string& Age)        { this->Age = Age; }
	void setOccupation (const std::string& Occupation) { this->Occupation = Occupation; }

	void createPerson();
	void editPerson();
	void displayPerson();
	void savePerson();
	void loadPerson();
    private:
	std::string Name,
		   Location,
		   Age,
		   Occupation;
};
# endif

That is all that should be in there, nothing else. Then you create a module, Person.cpp that includes this header, and in that file you implement the functions that aren't implemented in the class definition itself.

Also note that there is no "using namespace std" in the Person.h header file -- this has been discussed many times on this board and other places as to why it is not a good idea to place using clauses in headers. Instead, you see std:: appended to the string type.

Also, what you see in the header are all the headers that are necessary for Person.h to be able to live by itself. That's why <string> is included, because you are using std::string in the class. Your original header file did not #include <string> which was wrong.

Regards,

Paul McKenzie

[Paul McKenzie]

the problem now is:

one or more multiply defined symbols found!

Read my post and fix Person.h. It should not have class functions outside the class in that header. Those functions go into a separate, compilable, C++ module called preferably, Person.cpp.

Regards,

Paul McKenzie

[crisdeveloper]

ok, i´ll do it!

[crisdeveloper]

code updated:

Person.H

#ifndef PERSON_H
#define PERSON_H

using namespace std;

class Person
{    
	
public:

	//Constructor and Destructor Method:

	Person();
    ~Person();

	//funstions:

	void createPerson();
	void editPerson();
	void displayPerson();
	void savePerson();
	void loadPerson();

	//Accessor Methods:

	string getName       ()const { return Name; }
	string getLocation   ()const { return Location; }
	string getAge        ()const{ return Age; }
	string getOccupation ()const{ return Occupation; }

	void setName       (const string& Name)       { this->Name = Name; }
	void setLocation   (const string& Location)   { this->Location = Location; }
	void setAge        (const string& Age)        { this->Age = Age; }
	void setOccupation (const string& Occupation) { this->Occupation = Occupation; }
	
private:

	//private variables:

	string Name,
		   Location,
		   Age,
		   Occupation;


};

# endif

Cpp file

// Using_class_ in_ c++.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"

using namespace std;

//scope functions

Person::Person () {cout<<"\n\tBuilding a Person.";}
Person::~Person(){cout<<"\n\tDestroying a Person.";}

 void Person::createPerson()
{

	Person::editPerson();
	
}

void Person::editPerson()
{
   
	string TEMP;
    system ("CLS");
    cout<<"\n\n\t---------------------EDIT person ---------------------------";

    cout<<"\n\t Name: ";
	cin.ignore();
    getline (cin,TEMP);
    setName(TEMP);

    cout<<"\n\t Location ";
    getline (cin,TEMP);
    setLocation(TEMP);

    cout<<"\n\t Age: ";
    getline (cin,TEMP);
    setAge(TEMP);

    cout<<"\n\t Occupation: ";
    getline (cin,TEMP);
    setOccupation(TEMP);

}

void Person::displayPerson()
{
	
    system("CLS");
    cout<<"\n\n\t---------------------person information----------------------";
    cout<< "\n\tName: "      ,       getName();
    cout<< "\n\tLocation:" ,     getLocation();
    cout<< "\n\tAge: "  ,             getAge();
    cout<< "\n\tOccupation:" , getOccupation();
    cout<<"\n\n\t---------------------------------------------------------------\n\n";
}

void Person::savePerson()
{
	
    try
    {
        ofstream DATAFILE;
        DATAFILE.open("Data1.file",ios::out);

        DATAFILE <<getName       ()<<"\n";
        DATAFILE <<getLocation ()<<"\n";
        DATAFILE <<getAge   ()<<"\n";
        DATAFILE <<getOccupation ()<<"\n";

        DATAFILE.close(); //Prevents data from getting corrupt incase of sudden shutdown
        cout<<"\n\t Success! Data was saved to file.";
    }
    catch (exception x)
    {
        cout<<"\n\t File Error! Could not SAVE PERSON.";
    }

}

void Person::loadPerson()
{
	
    try
    {
        string TEMP;
        ifstream DATAFILE;
        DATAFILE.open("Data1.file",ios::in);
        getline (DATAFILE,TEMP);

        setName (TEMP);
        getline (DATAFILE,TEMP);

        setLocation (TEMP);
        getline (DATAFILE,TEMP);

        setAge (TEMP);
        getline (DATAFILE,TEMP);

        setOccupation (TEMP);
        DATAFILE.close();
    }
    catch (exception x)
    {
        cout<<"\n\t File Error! Unable to load data.";
    }
}



//end funstions scope


//main method


int main (int argc, char *argv[])
{

	Person cg;

	char choose[10] = "";
   
    cout<<"\n\t Personnel database 1.0\n";

    //system display ("CLS");

	//Loop

    while (choose [0] != 'q')
    {
        system ("CLS");
        cout<<"\n\t---------------------Main Menu---------------------\n";
        cout<<"\n\t| |\n";
        cout<<"\n\t| (c) Create person |\n";
        cout<<"\n\t| (e) edit information |\n";
        cout<<"\n\t| (d) display person |\n";
        cout<<"\n\t| (s) Save person |\n";
        cout<<"\n\t| (l) Load person |\n";
        cout<<"\n\t| (q) quit |\n";
        cout<<"\n\t| |\n";
        cout<<"\n\t---------------------------------------------------\n\n\t";
        cin>>choose;
        //system ("CLS");
        switch (choose [0])
        {
            //system ("CLS");
		case 'c': cg.createPerson(); break;
        case 'e': cg.editPerson(); break;
        case 'd': cg.displayPerson(); system ("pause"); break;
        case 's': cg.savePerson(); break;
        case 'l': cg.loadPerson(); break;
        case 'q': cout<<"\n\tExiting main menu..."; break;
        default :"\n\tInvalid input!";
        }
      
    }

	  system ("pause");
      return 0;

}

[crisdeveloper]

no errors on output
but i think the logic is wrong because the program is not saving data, and neither displaying.

:|

[VictorN]

code updated:

Person.H

#ifndef PERSON_H
#define PERSON_H

using namespace std;

class Person
{    
...
};

# endif

Did't you read what Paul wrote?

Where did you place the "using namespace std"? Hopefully it is not in the header file Person.h.

[VictorN]

no errors on output
but i think the logic is wrong because the program is not saving data, and neither displaying.

So why didn't you debug it to see what, where and why goes wrong?

[2kaud]

You have a problem with displayPerson

cout<< "\n\tName: "      ,       getName();

This is actually two statements separated by a comma. (The comma operator). First the cout is executed (which shows Name). Then the getName() function is executed with its return value not used. You need

cout << "\n\tName: "      <<       getName();

It is not normal practice to put the class function definitions in the header file. These usually go in a .cpp file. The .h header file normally just contains the class definition. Also it is not advised to put 'using' in a header file. If a header file uses string, cout etc then they are normally referenced via their full scoped name (std::cout, std::string etc). The 'using' statement would go in the .cpp file if required.

[2kaud]

no errors on output but i think the logic is wrong because the program is not saving data, and neither displaying.

See my post #42 re displaying. My copy of the program saves and loads data OK. 'type data1.file' at the command prompt to show the current data.

[crisdeveloper]

if i don´t put namespace in Person.h it not works because the strings types. what the best way to do it?

[2kaud]

if i don´t put namespace in Person.h it not works because the strings types. what the best way to do it?

See last para of my post #42. In the header file you use std::string, std::cout etc etc etc.