How to call a class within a function definition in c++ - c++

Question

Its my first time asking for help on programming. I have been working on a register program for my programming class for weeks which involves classes. Its rather frustrating for me. I have to use two classes: StoreItem and Register. StoreItem deals with the small list of items that the store sells. The register class deals mostly with processing the items, making a total bill and asking the user to pay with cash.
Here is the StoreItem.cpp file:
//function definition
#include <string>
#include <iostream>
#include "StoreItem.h"
#include "Register.h"
using namespace std;
StoreItem::StoreItem(string , double)
{
//sets the price of the current item
MSRP;
}
void StoreItem::SetDiscount(double)
{
// sets the discount percentage
MSRP * Discount;
}
double StoreItem::GetPrice()
{ // return the price including discounts
return Discount * MSRP;
}
double StoreItem::GetMSRP()
{
//returns the msrp
return MSRP;
}
string StoreItem::GetItemName()
{
//returns item name
return ItemName;
}
StoreItem::~StoreItem()
{
//deletes storeitem when done
}
Here is the Register.cpp:
Note that the last 5 function definitions in this one arent finished yet...
// definition of the register header
#include "Register.h"
#include "StoreItem.h"
using namespace std;
Register::Register()
{ // sets the initial cash in register to 400
CashInRegister = 400;
}
Register::Register(double)
{ //accepts initial specific amount
CashInRegister ;
}
void Register::NewTransAction()
{ //sets up the register for a new customer transaction (1 per checkout)
int NewTransactionCounter = 0;
NewTransactionCounter++;
}
void Register::ScanItem(StoreItem)
{ // adds item to current transaction
StoreItem.GetPrice();
// this probably isnt correct....
}
double Register::RegisterBalance()
{
// returns the current amount in the register
}
double Register::GetTransActionTotal()
{
// returns total of current transaction
}
double Register::AcceptCash(double)
{
// accepts case from customer for transaction. returns change
}
void Register::PrintReciept()
{
// Prints all the items in the transaction and price when finsished
}
Register::~Register()
{
// deletes register
}
My main question is where Register::ScanItem(StoreItem)... is there a way to correctly call a function from the storeItem Class into the Register scanitem function?

Answer 1

You have:
void Register::ScanItem(StoreItem)
{ // adds item to current transaction
StoreItem.GetPrice();
// this probably isnt correct....
}
This means that the ScanItem function takes one argument of type StoreItem. In C++ you can specify just the type and make the compiler happy. But if you intend to use the argument, you must give it a name. For example:
void Register::ScanItem(StoreItem item)
{
std::cout << item.GetItemName() << " costs " << item.GetPrice() << std::endl;
}

Answer 2

To be able to call a member function of the object you're passing as the parameter, you need to name the parameter, not just its type.
I suspect you want something like
void Register::ScanItem(StoreItem item)
{
total += item.GetPrice();
}