Vector not being populated when done through constructor - c++

Question

i'm assuming this is going to be a really simple fix but i've been staring at this code for so long my brains turned to mush.
For background, we've had to create a bank account program. I have a Account class and a Person class. My issue lies in the Person class. When a person gets instantiated it should automatically create an account object and push it into a vector. I also have a method that lets me add another account or delete one.
My issue is, when in my main class, the vector is coming up as 0 when using the v.size() method. I'll paste my code below, i'm very new to C++ and only just really been introduced to pointers so bare that in mind.
Person.cpp
#include "pch.h"
#include "Person.h"
#include <iostream>
using namespace std;
Person::Person()
{
Account acc1;
account.push_back(acc1);
}
void Person::newAccount() {
Account acc1;
account.push_back(acc1);
}
void Person::closeAccount(int index) {
cout << "Which account would you like to close?" << endl;
cin >> index;
account.erase(account.begin() + index);
}
Person::~Person()
{
}
Person.h
#pragma once
#include "Account.h"
#include <vector>
using namespace std;
class Person
{
public:
Person();
void newAccount();
void closeAccount(int index);
~Person();
private:
vector <Account> account;
};
Then in the main class I have:
#include "pch.h"
#include <iostream>
#include <iomanip>
#include <vector>
#include "Account.h"
#include "Person.h"
using namespace std;
int amount;
int years;
int balance;
vector <Account> accounts;
int main()
{
Person p;
Account a;
p.newAccount();
cout << accounts.size() << endl;
I left out the rest of the main class as that has nothing to do with this error but will post if needed.
Any help would be appreciated

Answer 1

The issue is that you are sampling the size of a global variable called
vector <Account> accounts;
This is not the same as the member variable you declared in your Person class called
vector <Account> account;
declared in your person class below:
class Person
{
public:
Person();
void newAccount();
void closeAccount(int index);
~Person();
private:
vector <Account> account;
};
These are two separate objects and your account appending is happening to your member variable within your Person Class. Change the output statement to report the size of the account vector of a Person instance through a function since the vector is private and it will report the correct size.
class Person
{
public:
Person();
void newAccount();
void closeAccount(int index);
~Person();
inline int GetAccountNum() const { return account.size(); }
private:
vector <Account> account;
};
int main()
{
Person p;
p.newAccount();
cout << p.GetAccountNum() << endl;
}
One popular coding convention C++ programmers use is to prefix member variables with m_ or m to avoid these kind of easy mistakes. It also can help to change the name of your vector to something other than just the plural form of the object.
Lastly, the Account object a, you are creating on the stack in the main function is not being used. This would produce a warning in most IDE's. If your intention was to add the account you created on the stack to your Person object's account vector, then you should create a function that accepts an account by reference and adds it to the member variable account vector for the Person object.
Follow the convention I listed above and it should help you avoid this mistakes in the future.