Separate the item class and the user class, into $2$ files

file.cpp and file.h and how to enter it in the main menu

User class

#include

#include

#include

using namespace std;

class User $\{$

private:

string username;

string password;

public:

User$($const string & user, const string & pass$)$ : username$($user$),$ password$($pass$)\{\}$

bool authenticate$($const string & inputUser, const string & inputPass$)$ const $\{$

return $($username $==$ inputUser$)$ && $($password $==$ inputPass$)$;

$\}$

static bool validateUser$($const string & inputUser, const string & inputPass$)\{$

ifstream file$("$user$.$txt$")$;

if $(!$file.is$\_$open$())\{$

cerr $<<$ "Error opening file" $<<$ endl;

return false;

$\}$

string storedUser, storedPass;

while $($file $>>$ storedUser $>>$ storedPass$)\{$

if $($storedUser $==$ inputUser && storedPass $==$ inputPass$)\{$

return true;

$\}$

$\}$

return false;

$\}$

$\}$;

Item class

#include

using namespace std;

class Item $\{$

private:

string name;

double price;

int quantity;

public:

Item$($const string & name, double price, int quantity $=0)$ : name$($name$),$ price$($price$),$ quantity$($quantity$)\{\}$

string getName$()$ const $\{$

return name;

$\}$

double getPrice$()$ const $\{$

return price;

$\}$

void setQuantity$($int newQuantity$)\{$

quantity $=$ newQuantity;

$\}$

int getQuantity$()$ const $\{$

return quantity;

$\}$

$\}$;