Ajouter une valeur C-string dans Structure C++

Question

J'essaie d'ajouter une valeur de chaîne (soit "Appliance", "Kitchenware" ou "Tool") au tableau de chaînes C "category [CATEGORY_SIZE]" situé dans la structure newItem mais une fois que l'utilisateur tente de le faire, le programme se termine. Quelqu'un peut-il expliquer pourquoi c'est ainsi et comment stocker correctement la valeur de chaîne si je le fais de manière incorrecte?

#include <fstream> 
#include <iostream> 
#include <sstream> 
#include <cctype> 
using namespace std; 

//Array sizes 
const int CATEGORY_SIZE = 15, DATE_SIZE = 12; 

//Declare structure for record 
struct Item 
{ 
    int SKU; 
    string category[CATEGORY_SIZE]; 
    int quantity; 
    double cost; 
    string date[DATE_SIZE]; 
}; 

int main() 
{ 
    //declare variables 
    int answer; 
    int cat; 
    int month; 
    string categoryChoice; 
    string monthChoice; 
    string theNumberString; 
    string theNewNumberString; 
    string fullDate; 
    int dayChoice; 
    int yearChoice; 
    char anotherRecord; 
    Item newItem; // to hold info about an item. 
    fstream dataFile; 

    fstream data("test.dat", ios::out | ios::binary); 

    cout << "This program allows you to store inventory data for appliances, kitchenware, 
      and tools in a file."; 

while (true) 
{ 

cout << "What would you like to do? :\n\n"; 
cout << "1. Add new records to the file\n"; 
cout << "2. Display a record in the file\n"; 
cout << "3. Change any record in the file\n"; 
cout << "4. Display total wholesale value of a particular item inventory.\n"; 
cout << "5. Display total wholesale value of a particular category inventory.\n"; 
cout << "6. Display total quantity of all items in the inventory." << endl; 
cout << "Please enter a number[1-6] or enter 0 to quit program: "; 
cin >> answer; 

if (answer == 0) 
{ 
    return 0; 
} 

if (answer < 0 || answer > 6) 
    cout << "That is not a valid response, please try again. "; 

if (answer == 1) 
{ 
    while (true) 
    { 
    cout << "Enter the following data about an item: \n\n"; 
    cout << "SKU Number (Stock Keeping Unit Number): "; 
    cin >> newItem.SKU; 
    cin.ignore(); //Skip over the remaining newline. 

    while (true) 
    { 
     cout << "Please enter what category the item falls in : \n"; 
     cout << "1. Appliance \n" "2. Kitchenware \n" "3. Tool: \n" << endl; 
     cout << "Please enter a choice [1-3]: "; 
     cin >> cat ; 

     if (cat < 1 || cat > 3) 
     cout << "Invalid choice. Please select again." << endl; 
     else if (cat == 1) 
     { 
     newItem.category[CATEGORY_SIZE] = "Appliance"; 
     break; 
     } 
     else if (cat == 2) 
     { 
     newItem.category[CATEGORY_SIZE] = "Kitchenware"; 
     break; 
     } 
     else if (cat == 3) 
     { 
     newItem.category[CATEGORY_SIZE] = "Tool"; 
     cout << newItem.category[CATEGORY_SIZE]; 
     break; 
     } 

     } 
    } 
    } 

Answer 1

newItem.category[CATEGORY_SIZE] = "Appliance"; 

(Et même): Vous avez un comportement non défini. Vous accédez au tableau hors limites parce que les indices tombent dans la plage [0, size). Utilisez un std::vector et soit push_back ou emplace_back (selon le support 11 C++):

std::vector<std::string> category; //you can construct this with an initial size 
... 
newItem.category.push_back("Appliance");