I have a question regarding a homework assignment.
I have two classes. One is called ticket.cpp, and the other is called TicketOrder.cpp
The main is within the ticket.cpp.
I am using a g++ compiler on Linux.
What I'm doing is trying to is print out a vector of a TicketOrder object called orders, but it gives me the following error:
ticket.cpp:57: error: no match for 'operator<<' in 'std::cout << orders. std::vector<_Tp, _Alloc>::operator[] with _Tp = TicketOrder, _Alloc = std::allocator'
Here is my code:
ticket.cpp
#include <iostream>
#include <vector>
#include <limits>
#include <cctype>
#include "TicketOrder.cpp"
using namespace std;
int main ()
{
int numberoftickets=0;
string input2;
char input3;
int profit=0;
vector <TicketOrder> orders;
int atotalmoney=0;
int btotalmoney=0;
int ctotalmoney=0;
int dtotalmoney=0;
int etotalmoney=0;
do
{
cout << "\nPick a ticket that you would like to buy: \n\n";
cout << "(A) Students without an activity card: $2.00 \n";
cout << "(B) Faculty and staff: $3.00 \n";
cout << "(C) USC alumni: $5.00 \n";
cout << "(D) UCLA students and alumni: $20.00 \n";
cout << "(E) Everyone else: $10.00 \n";
cin >> input3;
if (input3=='A')
{
cout << "How many tickets do you wish to buy? " <<endl;
if (numberoftickets >0)
{
TicketOrder order;
order.setQuantity(numberoftickets);
order.setType(input3);
orders.push_back(order);
for (int i=0; i< orders.size(); i++)
{
cout << orders[i];
}
}
}
else
{
cout << "Sorry did not recognize input, try again. " << endl;
}
} while (input3 != 'S');
TicketOrder.cpp:
#include <iostream>
using namespace std;
class TicketOrder
{
public :
//Getters
int getQuantity() const
{
return quantity;
}
char getType() const
{
return type;
}
//Setters
void setQuantity (int x)
{
quantity=x;
}
void setType(char y)
{
type =y;
}
private:
char type;
char quantity;
};
As the compiler is clumsily trying to explain, the code is missing an operator<< for the TicketOrder class.
class TicketOrder {
public:
friend std::ostream& operator<<(std::ostream& os, TicketOrder const& order) {
os << "Type: " << type << ", quantity: " << quantity;
return os;
}
char type;
int quantity;
};
(Note: you probably want to change quantity to int.)
You must add the operator << function as a friend to be able to print values from your TicketOrder objects with cout. Further reading
You're attempting to use the << operator on cout and a TicketOrder object. That is undefined. You should use the TicketOrder object to generate a string first, then output that via cout. Either that, or you can define the << operator for the TicketOrder class, as described in one of the other two answers.
Related
I have to make a Shopping Cart program for school, and there are more moving parts in this program than I've ever had to deal with. I'm trying to figure out why the function in my main.cpp can't recognize the object that I created in main(). It keeps saying that
the cart is not declared in the scope.
I still have to finish building out the menu, but I can't even get it to recognize the object that gets created in main.
I can see that the object is being properly created, because it can be manipulated within the main() no problem. Furthermore, I even have a few placeholder commands in there to get it working. The thing is that the homework assignment requires the menu to be in a function.
#include <iostream>
#include <string>
#include "ItemToPurchase.h"
#include "ShoppingCart.h"
using namespace std;
void PrintMenu()
{
while (true)
{
string choice;
cout << "MENU" << endl;
cout << "a - Add item to cart" << endl;
cout << "d - Remove item from cart" << endl;
cout << "c - Change item quantity" << endl;
cout << "i - Output item's descriptions" << endl;
cout << "o - Output shopping cart" << endl;
cout << "q - Quit" << endl;
cout << endl;
cout << "Choose an option: " << endl;
cin >> choice;
if (choice == "a") {
cart.GetDate();
}
else if (choice == "d") {
}
else if (choice == "c") {
}
else if (choice == "i") {
}
else if (choice == "o") {
}
else if (choice == "q") {
break;
}
else {
cout << "That is not a valid choice" << endl;
}
}
}
int main()
{
string name;
string date;
cout << "Enter customer's name: " << endl;
cin >> name;
cout << "Enter today's date: " << endl;
cin >> date;
cout << endl;
cout << "Customer name: " << name << endl;
cout << "Today's date: " << date << endl;
ShoppingCart cart(name, date);
ItemToPurchase apple("apple", 1, 4, "apple");
cout << cart.GetDate();
cart.AddItem(apple);
cout << cart.GetNumItemsInCart();
PrintMenu();
}
#ifndef SHOPPINGCART_H
#define SHOPPINGCART_H
#include <string>
#include <iostream>
#include <vector>
#include "ItemToPurchase.h"
using namespace std;
class ShoppingCart
{
private:
string customerName = "none";
string currentDate = "January 1, 2016";
vector<ItemToPurchase> cartItems;
public:
ShoppingCart(string name, string date);
string GetCustomerName() const;
string GetDate();
void AddItem(ItemToPurchase);
void RemoveItem(string);
void ModifyItem();
int GetNumItemsInCart();
double GetCostofCart();
void PrintTotal();
string PrintDecriptions();
};
#endif
#include <iostream>
#include <string>
#include <vector>
#include "ShoppingCart.h"
using namespace std;
ShoppingCart::ShoppingCart (string name, string date){
customerName=name;
currentDate= date;
}
string ShoppingCart::GetCustomerName() const
{
return customerName;
}
string ShoppingCart::GetDate()
{
return currentDate;
}
void ShoppingCart::AddItem(ItemToPurchase item)
{
cartItems.push_back(item);
}
void ShoppingCart::RemoveItem(string name)
{
for (int i = 0; i < cartItems.size(); i++)
{
if (cartItems.at(i).GetName() == name)
{
cartItems.erase(cartItems.begin() + i);
}
else
{
cout << "Item not found in cart. Nothing removed." << endl;
}
}
}
int ShoppingCart::GetNumItemsInCart(){
int number;
number = cartItems.size();
return number;
}
double ShoppingCart::GetCostofCart()
{
double sum = 0.0;
for (int i = 0; i < cartItems.size(); i++)
{
sum += cartItems[i].GetQuantity() * cartItems[i].GetPrice();
}
return sum;
}
#include "ItemToPurchase.h"
void ItemToPurchase::SetName(string SetItemName){
itemName = SetItemName;
}
void ItemToPurchase::SetPrice(int SetItemPrice){
itemPrice = SetItemPrice;
}
void ItemToPurchase::SetQuantity(int SetItemQuantity){
itemQuantity = SetItemQuantity;
}
string ItemToPurchase::GetName() const {
return itemName;
}
int ItemToPurchase::GetPrice() const {
return itemPrice;
}
int ItemToPurchase::GetQuantity() const {
return itemQuantity;
}
#include <string>
#include <iostream>
#ifndef ITEMTOPURCHASE_H
#define ITEMTOPURCHASE_H
using namespace std;
class ItemToPurchase
{
public:
ItemToPurchase(string a, int b, int c, string d)
{itemName = a;
itemPrice = b;
itemQuantity = c;
itemDescription =d;
}
void SetName(string SetItemName);
void SetPrice(int SetItemPrice);
void PrintItemDescription();
void SetQuantity(int SetItemQuantity);
string GetName() const;
int GetPrice() const;
int GetQuantity() const;
void SetDescription() const;
string GetDiscription() const;
void PrintItemCost() const;
private:
string itemName;
int itemPrice;
int itemQuantity;
string itemDescription;
};
#endif
[...], but I can't even get it, to recognize the object that gets created in main().
The main() and the PrintMenu() are two different functions with different scope. One can not know the variables from other, unless you pass or make known by any means.
In your case, you can pass the ShoppingCart object (i.e cart) from main() to the PrintMenu function, so that inside it will know which cart you meant for:
void PrintMenu(ShoppingCart& cart)
// ^^^^^^^^^^^^^^^^^^^^
{
// ...
}
and call the function from main() with the ShoppingCart object.
PrintMenu(cart);
That being said;
Please do not practice with using namespace std;. Read more: Why is "using namespace std;" considered bad practice?
If the member function does not modify the member, you should mark the function as const. Applies for all the getters of both ItemToPurchase and ShoppingCart classes.
When you return a non-trivial copyable objects like std::string in a getter, you should be avoiding copying. That means you might want to have changes like as below for all your getters which returns std::string:
const std::string& GetDate() const /* noexcept */
{
return currentDate;
}
This line in PrintMenu is the problem:
cart.GetDate();
The compiler looks for something called cart within the scope of that function, which does not exist. Once way to resolve this, is to pass a reference to the cart created in main to the PrintMenu function:
void PrintMenu(ShoppingCart &cart){
and call the function like this:
PrintMenu(cart);
Note that because, in the future, you'll want to modify cart in the menu, you'll need to pass it as a reference (i.e. with &) and not as a copy or constant reference.
I am trying to add setter to my project as a requirement but am stuck on making it work. I commented out the areas I have to add it but everything I have looked up has not worked. I know I am close but everything seems to not work.
#include "pch.h"
#include <string>
#include <conio.h>
#include <iostream>
using namespace std;
template <class T>
class Holder
{
private:
T thing;
int number; //add an integer data member that stores the number of data members of whatever class is stored in "thing"
public:
void standardInput();
void standardOutput();
void setNumber(int); // declare a setter function for the new data member
};
template <class T>
void Holder<T>::standardInput()
{
cout << endl;
cout << "You will be asked to enter " << n.setNumber << " items" << endl; // a line of output that use the data member with the number
cin >> Holder<T>::thing;
}
template <class T>
void Holder<T>::standardOutput()
{
cout << endl;
cout << "Here's the data you requested: " << endl;
cout << Holder<T>::thing << endl;
}
template<class T>
void Holder<T>::setNumber(int n) //implement the setter function for the new data member
{
setNumber = n;
}
// This is the first of two custom classes
class Student
{
friend ostream& operator<<(ostream&, Student&);
friend istream& operator>>(istream&, Student&);
private:
string name;
double tuiton;
};
ostream& operator<<(ostream& out, Student& a)
{
out << "The Student " << a.name << " Tuiton is: " << a.tuiton << endl;
return out;
}
istream& operator>>(istream& in, Student& a)
{
cout << "Enter the name of student: ";
in >> a.name;
cout << "What is the Price of tuiton? ";
in >> a.tuiton;
return in;
}
// This is the second of two custom classes
class FastFood
{
friend ostream& operator<<(ostream&, FastFood&);
friend istream& operator>>(istream&, FastFood&);
private:
int valueNumber;
double cost;
};
ostream& operator<<(ostream& out, FastFood& a)
{
out << " The Combo Number is " << a.valueNumber << " .It costs " << a.cost << endl;
return out;
}
istream& operator>>(istream& in, FastFood& a)
{
cout << "What is the Combo number? ";
in >> a.valueNumber;
cout << "Enter cost: ";
in >> a.cost;
return in;
}
int main()
{
cout << "For an integer: " << endl;
Holder<int> val;
// use the setter to store 1.
val.standardInput();
val.standardOutput();
cout << "For a Student:" << endl;
Holder<Student> aCollegeStudent;
// use the setter to store 2.
aCollegeStudent.standardInput();
aCollegeStudent.standardOutput();
Holder<FastFood> vMeal;
// use the setter to store 3.
vMeal.standardInput();
vMeal.standardOutput();
cout << endl;
system("pause");
return 0;
}
This is supposed to ask the integer along with the student and fastfood information. I required to add a setter in the template but wont need to use a getter due to standard input and output just cant figure out the right way to do it.
1st of all Im newBee at C++ programming.so please apologize if i make lots of mistake while asking questions.
My problem is:
i create class which contain private variable and Methods like below:
class Records{
private:
string name;
public:
string n;
void setValue(){
cout << "Enter name" << endl;
cin >> name;
}
void getValue(){
n = name;
cout << "Name is: " << n << endl;
}
};
I have run your code on GCC compiler, it's successfully worked. Please, see complete example :
#include <iostream>
using namespace std;
class Records{
private:
string name;
public:
string n;
void setValue(){
cout << "Enter name" << endl;
cin >> name;
}
void getValue(){
n = name;
cout << "Name is: " << n << endl;
}
};
int main()
{
Records r;
r.setValue();
r.getValue();
}
I am trying this piece of code in vs 2008
#include <stdio.h>
#include <iostream>
#include <string>
typedef struct _first
{
int age;
std::string name;
}first;
typedef struct _second
{
int age;
char name[20];
}second;
void copy_structure()
{
first s;
second f;
f.age = 15;
cout<<"Enter the name"<<endl;
fgets(f.name, 20, stdin);
memcpy(&s,&f,20);
cout << "Name: " << s.name << endl;
cout << "Age: "<< s.age << endl;
}
int main()
{
copy_structure();
return 0;
}
while building I didn't get any error but when I run, name field is empty over here
cout << "Name: " << s.name << endl;
I am not getting any output over here, can somebody help me to solve this issue.
You should use an approach based on member-wise copying. For example
void copy_structure()
{
first f;
^^
second s;
^^
s.age = 15;
cout<<"Enter the name"<<endl;
fgets(s.name, 20, stdin);
f.age = s.age;
f.name = s.name;
cout << "Name: " << f.name << endl;
cout << "Age: "<< f.age << endl;
}
Otherwise the internals of the object name of the type std::string will be overwritten and the program will have undefined behaviour.
This looks like C but not like C++... Your current code will also brick your std::string instance. memcpy is dangerous and should not be used, unless you have a very, very good reason. I never had a reason for this so far.
My suggestion:
#include <iostream>
#include <string>
using namespace std;
struct second
{
int age;
char name[20];
};
struct first
{
int age;
string name;
first& operator=(const second& rhs);
};
// some operator for copying
first& first::operator=(const second& rhs)
{
age = rhs.age;
name = rhs.name;
return *this;
}
int main()
{
first s;
second f;
f.age = 15;
cout << "Enter your name" << endl;
cin >> f.name;
s = f;
cout << "Name: " << s.name << endl;
cout << "Age: " << s.age << endl;
return 0;
}
This is improvable, of course. You would usually rather use classes than structs. And you would might also have an operator>> for second.
So, the problem is several errors at compile time.
ReadMovieData(string* title, string* director) cannot convert from movieInfo to string*
DisplayMovieData(string title, string director) cannot convert from movieInfo to string
No operator found which takes a right-hand operand of type 'movieInfo' (or there is no acceptable conversion.
The bottom error happens twice in DisplayMovieData() so I wrote it once for simplicity sake.
The ReadMovieData function should accept a structure pointer reference variable and the DisplayMovieData function should accept a MovieInfo structure variable.
The main function creates an array of 2 MovieInfo struct variables and the other functions should be called on an element of the array.
The code I have finished is below.
#include <stdafx.h>
#include <string>
#include <iomanip>
#include <iostream>
using namespace std;
//prototypes
int ReadMovieData(string* title, string* director);
int DisplayMovieData(string title, string director);
struct movieInfo {
string title, director;
};
int main(){
const int SIZE = 2;
movieInfo movieList[SIZE];
movieInfo movie;
//supposed to assign data to movieList[i] at some point
for (int i = 0; i < SIZE; i++){
ReadMovieData(movie, movie);
DisplayMovieData(movie, movie);
}
return 0;
}
int ReadMovieData(movieInfo &title, movieInfo &director){
movieInfo movie;
//get the movie name
cout << "What is the movie? ";
cin.ignore();
cin >> movie.title;
//get the movie director
cout << "What is the director of " << movie.title << "?";
cin.ignore();
cin >> movie.director;
return 0;
}
int DisplayMovieData(movieInfo title, movieInfo director){
cout << "The movie name is: " << title << endl;
cout << "The director of " << title << " is: " << director << endl;
return 0;
}
There are mismatches between your function prototypes and their definitions, as you can see comparing the parameter types in both.
Note that since you defined a structure for the movie info, you can directly pass it to the reading and displaying functions (instead of passing the single structure data member strings).
You may want to read the following compilable code:
#include <iostream>
#include <string>
using namespace std;
struct MovieInfo {
string title;
string director;
};
void ReadMovieData(MovieInfo& movie);
void DisplayMovieData(const MovieInfo& movie);
int main() {
const int SIZE = 2;
MovieInfo movieList[SIZE];
for (int i = 0; i < SIZE; i++) {
ReadMovieData(movieList[i]);
DisplayMovieData(movieList[i]);
}
}
// Since movie is an output parameter in this case, pass by non-const reference.
void ReadMovieData(MovieInfo& movie) {
//get the movie name
cout << "What is the movie? ";
cin >> movie.title;
//get the movie director
cout << "What is the director of " << movie.title << "?";
cin >> movie.director;
}
// Since movie is an input parameter in this case, pass by reference to const.
void DisplayMovieData(const MovieInfo& movie) {
cout << "The movie name is: " << movie.title << endl;
cout << "The director of " << movie.title
<< " is: " << movie.director << endl;
}
The errors are pretty explanatory and clear - your function takes string* but you're passing movieInfo - unrelated types can't just magicaly convert one to another.
What you probably want is pass the data members of movieInfo:
ReadMovieData(&movie.title, &movie.director);
It would be better if arguments were not pointers - use references instead. Where you won't be changing the arguments, the references should be to const type.
Even better, why not just pass moveInfo
ReadMovieData(movieInfo& movie);
and let the function deal with the internals of the class? This better encapsulates data and doesn't lead to spaghetti code quite so fast.
Also, the declarations and definitions need to match (otherwise you'd be overloading) - you're using pointers in some places and references/values in others.
Finally, here's how an overload of operator<< might look like:
std::ostream& operator<<(std::ostream& os, const movieInfo& m)
{
return os << "Title: " << m.title << ", Director: " << m.director;
}
Your class movieInfo does not have an overloaded << operator, which is necessary is you want to work with iostream, however, you can pass the strings contained in movieInfo:
int DisplayMovieData(string &title, string &director) { }
Call like:
DisplayMovieData(movie.title, movie.director);
You are declaring the function with this signature
int ReadMovieData(string* title, string* director);
but you're defining it using
int ReadMovieData(movieInfo &title, movieInfo &director) {
// ...
}
These don't match!
The code is totally invalid. I suppose the valid code should look the following way
#include <stdafx.h>
#include <string>
#include <iomanip>
#include <iostream>
using namespace std;
struct movieInfo
{
string title, director;
};
//prototypes
movieInfo ReadMovieData();
void DisplayMovieData( const movieInfo & );
int main()
{
const int SIZE = 2;
movieInfo movieList[SIZE];
//supposed to assign data to movieList[i] at some point
for ( int i = 0; i < SIZE; i++ )
{
movieList[i] = ReadMovieData();
DisplayMovieData( movieList[i] );
}
return 0;
}
movieInfo ReadMovieData()
{
movieInfo movie;
//get the movie name
cout << "What is the movie? ";
cin.ignore();
cin >> movie.title;
//get the movie director
cout << "What is the director of " << movie.title << "?";
cin.ignore();
cin >> movie.director;
return movie;
}
void DisplayMovieData( const movieInfo &movie )
{
cout << "The movie name is: " << movie.title << endl;
cout << "The director of " << movie.title << " is: " << movie.director << endl;
}