Defining a vector within a custom class - c++

Question

I'm trying to simply use a vector within one of my classes. When trying to access the vector it tells me that it's undefined (but I've defined it in my header).
I have two classes, Person and Dog. A person can own one or more dogs so I want to add each dog a person owns into an array. This should be real simple so this problem is really starting to get to me. Here's some code:
The class Person.cpp:
#include "Person.h"
#include "stdafx.h"
#include <iostream>
using namespace std;
Person::Person(string name, string address, int age)
:name(name),
address(address),
age(age)
{}
int Person::getAge(){
return age;
}
std::string Person::getDogInfo(int index){
}
void Person::addDog(string dogName, string breed){
dogCollection.push_back(Dog(dogName, breed));
}
std::vector<Dog> getDogs(){
return dogCollection; //dogCollection undefined error here
}
And here's Person.h:
#ifndef Person_H
#define Person_H
#include <vector>
#include "Dog.h"
using namespace std;
class Person{
public:
Person(string name, string address, int age);
string getName(){return name};
string getAddress(){return address};
void addDog(string dogName, string breed);
string getDogInfo(int index);
std::vector<Dog> getDogs();
int getAge();
private:
string name;
string address;
int age;
std::vector<Dog> dogCollection;
};
#endif
If you want to have a look at my dog classes I'll paste them as well:
Dog.cpp:
#include "stdafx.h"
#include <iostream>
#include "dog.h"
Dog::Dog(string dogName, string breed)
:dogName(dogName),
breed(breed){}
std::string Dog::Dog.getDogName(){
return dogName;
}
std::string Dog::Dog.getBreed(){
return breed;
}
and Dog.h:
#ifndef Dog_H
#define Dog_H
#include <iostream>
using namespace std;
class Dog{
public:
Dog(std::string dogName, std::string breed);
std::string getDogName();
std::string getBreed();
private:
std::string dogName;
std::string breed;
};
#endif
Also, I just want to add that this is no homework. I'm used to java and I'm only trying to learn some C++ since I need it for future work.
EDIT: Updated the code

Answer 1

std::vector<Dog> dogCollection; // here im defining dogCollection, no error here!
There actually is an problem here - class Dog isn't known to the compiler at this point.
You can solve this by either including Dog.h before Person.h in Person.cpp, or better add an #include "Dog.h" at the top of Person.h.

Answer 2

This is incorrect (and unrequired):
dogCollection = new std::vector<Dog>; // Remove this line.
as dogCollection is not a std::vector<Dog>*.
This is also incorrect:
void Person::addDog(string dogName, string breed){
Dog *newDog = new Dog(dogName, breed);
dogCollection.push_back(newDog);
}
as dogCollection contains Dog instances, not Dog*. Change to:
void Person::addDog(string dogName, string breed){
dogCollection.push_back(Dog(dogName, breed));
}
There is a problem with all of constructors:
Person::Person(string name, string address, int age){
name=name;
address=address;
age=age;
}
This is assigning the argument name to itself: it is not assigning to the member name. Same for address and age and similarly for the constructors of the other classes. Use initializer list:
Person::Person(string name, string address, int age) :
name(name),
address(address),
age(age)
{}
This method does not return a std::string:
string Person::getDogInfo(int index){
}
EDIT:
Missing class qualifier:
std::vector<Dog> getDogs(){
return dogCollection; //dogCollection undefined error here
}
means this is just a free function, with no association to class Person and therefore no access to dogCollection.
Change to:
std::vector<Dog> Person::getDogs(){
return dogCollection;
}

Answer 3

There are several problems with your code, and most of the other answers have pointed them out - mostly regarding the use of new when it should not be used. (Are you a C# programmer, moving to C++?)
However, there are problems with the #include directives as well. As #Bo mentioned, since Person uses Dog, you should include that header in Person.h. But Person also uses vector so that header should be included there as well. So Person.h should start with...
#include <vector>
#include "Dog.h"
Then in Person.cpp you don't have to include those files.
As a general rule (you can learn about "forward declaration" later), any types referenced in a header should be #included in that header.