c++ - 数组在返回时丢失值(库存/菜单程序)C++

Question

所以在很大程度上我明白我做错了什么，问题是我不知道如何解决它。

目标:这是一个必须包含可操作的菜单和库存管理功能的商店管理系统。为此，我使用数组来添加商店的商品、它们的描述和它们的数量。所有数组都部分填充到第三个元素，最大值为十个元素。

问题:当程序第一次运行时，它可以正常工作，用户可以看到他们的库存、描述和数量。然而，当他们退出菜单并返回库存时，第三个元素之后的所有内容都会被清除。这是由于声明将第三个元素之后的数组初始化为 0。我该如何解决这个问题以保证用户保存了他们的库存并且可以在返回时查看它？

#include <iostream>       
#include <vector>
#include <fstream>
#include <string>
#include <cmath>
#include <cstdlib>


using namespace std;

//declarations
int mainMenu(); //done
void inventoryMgmt();
void addInv(); //working on
void invView(string x[], int sizeofArray, string y[], int secondArray, int z[], int thirdArray);
void editor(string x[], int sizeofArray, string y[], int secondArray, int z[], int thirdArray);
void customerReciept();  //done
void calculatePrice(); //done
void exit(); //done

const double massTax = 0.0625;

//main
int main() {
    int choice;
    bool repeat = true;

    while (repeat = true) {
        choice = mainMenu();

        switch (choice) {
        case 1:
            customerReciept();
            break;
        case 2:
            inventoryMgmt();
            break;
            //case 3:
            //itemSearcher();
            //break;
        case 4:
            exit();
            repeat = false;
            break;
        }
    }

    return 0;
}

//main menu function ***done
int mainMenu() {
    cout << "\n\n\t\t\t\t Welcome to the Massasoit Store Management System " << endl;
    cout << "\t\t\t\t ________________________________________________ \n\n";
    cout << "\t\t\t\t\t Main Menu: " << endl;
    cout << "\t\t\t\t\t\t 1. Customer Reciept" << endl;
    cout << "\t\t\t\t\t\t 2. Inventory Management" << endl;
    cout << "\t\t\t\t\t\t 3. Item Search" << endl;
    cout << "\t\t\t\t\t\t 4. Exit" << endl << endl;
    int choice;
    cout << "\t\t\t\t\t\t Where do you need to go?: ";
    cin >> choice;

    while (choice < 1 || choice > 4) {
        cout << "\t\t\t\t\t Incorrect Selection Please Select Again: ";
        cin >> choice;
    }
    return choice;
}

//customer reciept function  **done
void customerReciept() {
    cout << "\n\n\t\t\t\t Welcome to the Massasoit Store: Customer Reciept " << endl;
    cout << "\t\t\t\t ________________________________________________ \n\n";
    cout << "\t\t\t\t\t Receipt Menu: " << endl;
    cout << "\t\t\t\t\t\t 1. Calculate Receipt" << endl;
    cout << "\t\t\t\t\t\t 2. Return to Main" << endl;
    int recieptChoice;
    cout << "\t\t\t\t\t\t Where do you need to go?: ";
    cin >> recieptChoice;
    while (recieptChoice < 1 || recieptChoice > 2) {
        cout << "Invalid Selection Please Choose Again: ";
        cin >> recieptChoice;
    }
    if (recieptChoice == 1) {
        calculatePrice();
    }
}

void calculatePrice() {
    double cost;
    double taxAmount;
    int numOfItems;
    double finalCost = 0;
    char tax;
    int i;
    cout << "\n\n\t\t\t\t Welcome to the Massasoit Store: Customer Reciept " << endl;
    cout << "\t\t\t\t ________________________________________________ \n\n";
    cout << "How many items were purchased?: ";
    cin >> numOfItems;
    for (i = 0; i < numOfItems; i++) {
        cout << "What did item " << i + 1 << " cost? $";
        cin >> cost;
        cout << "Is this item taxable? (y/n):";
        cin >> tax;
        if (tax == 'y' || tax == 'Y') {

            taxAmount = (cost * massTax);
            cost = taxAmount + cost;
            finalCost = cost + finalCost;
        }
        else {
            finalCost = cost + finalCost;
        }
    }
    cout.setf(ios::fixed);
    cout.setf(ios::showpoint);
    cout.precision(2);
    cout << "This customer's total is $" << finalCost << endl;
}

void inventoryMgmt() {

    int invChoice;
    cout << "\n\n\t\t\t\t\t Welcome to Inventory Management " << endl;
    cout << "\t\t\t\t ______________________________________________ \n\n";
    cout << "\t\t\t\t\t Inventory Settings: " << endl;
    cout << "\t\t\t\t\t\t 1. Add/View & Edit/Delete Inventory" << endl;
    cout << "\t\t\t\t\t\t 2. Return to Main" << endl;
    cout << "\t\t\t\t\t\t Where do you need to go?: ";
    cin >> invChoice;
    cout << endl << endl;
    while (invChoice < 1 || invChoice > 2) {
        cout << "Invalid Selection Please Choose Again: ";
        cin >> invChoice;
    }
    if (invChoice == 1) {

        addInv();
    }
    if (invChoice == 2) {
        //edit/delete();
    }
}

void addInv() {
    //so when this is called, everything is initialized to 0 which makes it wipe the memory
    //when the user comes back to it from the menu.

    const int description = 20; //this allows a short description for each item
    const int counter = 10; //slots of inventory allowed
    int quantity[10] = {10, 15, 45};
    string itemArray[counter] = { "Hot Drinks", "Cold Drinks", "Books"};
    string descriptionArray[description] = { "Coffee, Tea etc", "Water, juice, etc", "Texts, notebook, etc"};
    char addChoice;
    int destination;
    cout << "\t\t\t\t\t\t 1. Add/View" << endl;
    cout << "\t\t\t\t\t\t 2. Edit/Delete" << endl;
    cout << "\t\t\t\t\t\t 3. Exit to Main" << endl;
    cout << "\t\t\t\t\t\t Where would you like to go?: " << endl;
    cin >> destination;

    while (destination < 1 || destination > 3) {
        cout << "Invalid Selection, Please Select Again: ";
        cin >> destination;
    }

    if (destination == 1) {
        cout << "Would you like to add an item? (y/n): ";
        cin >> addChoice;
        int i = 3;      //these two are initialized to three to ensure that the store 
        int ii = 3;     //will always have hot drinks, cold drinks and books as options 
        while (addChoice == 'y' && i < counter) {

            cout << "What would you like to add?: ";
            cin >> itemArray[i];
            cout << "You have added \"" << itemArray[i] << "\" to the inventory\n";
            cout << "Please Provide a Brief Description: ";
            cin.ignore();
            getline(cin, descriptionArray[ii]);
            cout << "You've described \"" << itemArray[i] << "\" as  \"" << descriptionArray[i] << "\"" << endl;
            cout << "What is the quantity of " << itemArray[i] << " in stock?";
            cin >> quantity[i];
            cout << "Would you like to add another item?";
            cin >> addChoice;
            i++;
            ii++;
            if (i > counter) {
                cout << "**INVENTORY LIMIT REACHED*** ";
            }
        }
        invView(itemArray, 10, descriptionArray, 10, quantity, 10); //working on this. //so use this for view, edit, and delete.
    }
}

void invView(string x[], int sizeofArray, string y[], int secondArray, int z[], int thirdArray) {   //add quantity

    int i = 0;
    int ii = 0;
    int iii = 0;
    cout << "Your inventory consists of: ";
    while (i < sizeofArray && x[i] != "" && ii < secondArray && y[i] != "" && iii < thirdArray) {
        cout << x[i] << " - " << y[i] << " | Quantity: " << z[i] << endl;
        i++;
        ii++;
    }
}

void editor(string x[], int sizeofArray, string y[], int secondArray, int z[], int thirdArray) {
    cout << "Which item would you like to edit?";
}

void exit() {
    cout << "\n\n\t\t\t\t Welcome to the Massasoit Store Management System " << endl;
    cout << "\t\t\t\t ________________________________________________ \n\n";
    cout << "\t\t\t\t Thank you for using the Massasoit Store Management System" << endl;
    exit(1);
}

我包含了整个代码以备不时之需。问题集中在 inventoryMgmt() 和 addInv() 函数上。在此先感谢您的帮助!

Answer 1

在addInv() 中，所有数组都是本地的。一旦该函数执行完毕，所有局部变量都将被释放，从而导致您的删除。尝试将它们放在 addInv() 函数之外:

    int main(){
        int quantity[10] = {10, 15, 45};
        string itemArray[counter] = { "..."};
        string descriptionArray[description] = { "..."};

    void addInv() {...}
    }