Unresolved Externals, Unresolved external symbol LNK 1120

Question

I am making a bank account program and can not figure out why I keep getting the following error:

Error 5 error LNK1120: 1 unresolved externals

I have a superclass BankAccount and a child class Checking Account.

Bank Account .h:

#pragma once
#include <iostream>
#include <string>
#include <vector>
using namespace std;

class BankAccount
{
public: 
    BankAccount::BankAccount();
    BankAccount::~BankAccount();
    virtual void depsoit(double money) = 0;
    virtual double withdraw(double money) = 0;
    virtual double getBalance() = 0;
    virtual void endOfMonth() = 0;

private:
    double balance;

};

Bank account .cpp

#include "BankAccount.h"
#include <iostream>
#include <vector>
using namespace std;

BankAccount::BankAccount()
{
    balance = 0;
}

BankAccount::~BankAccount()
{

}

CheckingAccount.h

#pragma once
#include "BankAccount.h"
#include <vector>
#include <iostream>
using namespace std;
class CheckingAccount :
    public BankAccount
{
public:
    CheckingAccount();
    ~CheckingAccount();
    void depsoit(double money);
    double withdraw(double request);
    double getBalance();
    void endOfMonth();
private:
    double checkingBalance=0;
    int transactionLimit = 5;
    float fee = .05;
    double fees=0;
    vector <double> feeTransactions;

};

CheckingAccount.cpp

#include "CheckingAccount.h"
#include <iostream>
#include <vector>
using namespace std;

CheckingAccount::CheckingAccount()
{
    checkingBalance = 0;
}



CheckingAccount::~CheckingAccount()
{

}



void CheckingAccount::depsoit(double money)
{
    if (transactionLimit > 0)
    {
        transactionLimit--;
        cout << "You have " << transactionLimit << " transactions left";
        checkingBalance += money;

    }
    else
    {
        feeTransactions.push_back(money);
        cout << "Your transaction went through but you incurred a fee";
        checkingBalance += money;
    }
}
double CheckingAccount::withdraw(double request)
{
    if (checkingBalance < request)
    {
        cout << "Sorry you do not have the available funds";
        return 0.0;
    }
    else if (transactionLimit > 0)
    {
        transactionLimit--;
        cout << "You have " << transactionLimit << " transactions left";
        checkingBalance -= request;
        return request;

    }
    else
    {
        feeTransactions.push_back(request);
        cout << "Your transaction went through but you incurred a fee";
        checkingBalance -= request;
        return request;
    }

}

double CheckingAccount::getBalance()
{
    return checkingBalance;
}

void CheckingAccount::endOfMonth()
{
    for (int i = 0; i < feeTransactions.size(); i++)
    {
        fees = feeTransactions[i] * fee;
    }
    checkingBalance -= fees;
}

And finally MAIN.CPP

#include "CheckingAccount.h"
#include <iostream>
#include <vector>

using namespace std;

int main()
{

    CheckingAccount test();
    test().getBalance();

    //system("PAUSE");
    return 1;
}

The error message again is:

Error 4 error LNK2019: unresolved external symbol "class CheckingAccount __cdecl test(void)" (?test@@YA?AVCheckingAccount@@XZ) referenced in function _main C:...Main.obj Assignment1Part3A

Answer 1

Well the error tells you exactly what's the problem. It's in your main: test().getBalance();. You are calling test as it was a function, but it's an object name. It should be just test.getBalance(). The previous line should be without the () too, but they should be fine there, because the compiler is treating them as a constructor in that case.

Answer 2

You are not declaring a variable of type CheckingAccount here:

CheckingAccount test();

What you are doing is declaring a function test which returns an object of type CheckingAccount and takes in no parameters.

Do it as follows:

CheckingAccount test{};

You should call getBalance as follows:

test.getBalance(); and not test().getBalance();