主 cpp 外部 while 循环不 go 回到 switch 语句选项，内部 while 循环工作正常

Question

The program asks the user which department they would like to enter. Goes into that department and then asks user what would they like to do inside that department. At end of whatever user would like to do the inner while loop asks "what is next?". If user enters "0" they are taken back to the question of "which department would they like to enter, user enters the index for corresponding department, but the loop does not go back into whichever department the user chooses.

In short: the outer while loop executes, and proceeds to the switch statements with inner while loops, but when the user returns to the outer while loop - that loop does not reenter the user specified department.

// MAIN PROPGRAM

#include "client.h" // include appropriate .h files
#include "salesrep.h"
#include "product.h"
#include "sales.h"

#include <iostream> // include appropriate libraries
#include <fstream>
#include <cstdlib>
#include <string>
#include <vector>
#include <algorithm>
#include <iomanip>

using namespace std; // standard namespace

int main() {

    Client alpha; // client class object
    SalesRep beta; // sales rep class object
    Product gamma; // product class object
    Sales delta; // sales class object
    int index; // index to traverse main menu
    int subIndex; // index to traverse sub menu

    cout << "Welcome to Wedling Central; we are happy you are here!" << endl; // greeting
    cout << "Please select which department you would like to enter:" << endl; // orientation
    cout << "Clients (Enter: 1)" << endl; // directories
    cout << "Sales reps (Enter: 2)" << endl;
    cout << "Products (Enter: 3)" << endl;
    cout << "Sales (Enter: 4)" << endl;
    cout << "Quit (Enter: 0)" << endl; // option to exit
    cin >> index; // user input index for main menu
    cin.ignore(); // ignore cin after index input

    while (index != 0) { // while user does not wish to exit program

    switch(index) {
        case 1: // client department

        while (subIndex != 0){ // while user does not wish to return to main menu

            cout << "What would you like to do?" << endl; // prompt
            cout << "Modify client (Enter: 1)" << endl; // options
            cout << "Add new client (Enter: 2)" << endl;
            cout << "Get a client's info (Enter: 3)" << endl;
            cout << "View clients (Enter: 4)" << endl;
            cout << "Go back to main menu (Enter: 0)" << endl; // return to main menu

            cin >> subIndex; // user input for sub menu
            cin.ignore(); // ignore cin after sub index input
            

            switch(subIndex) { // options within department
                case 1:

                    alpha.SetModifyClient(); // update a client
                    
                    break; // return to sub menu

                case 2:

                    alpha.SetNewClient(); // add new client

                    break; // return to sub menu

                case 3:

                    alpha.GetSpecificClientInfo(); // view specific client's information

                    break; // return to sub menu

                case 4:

                    alpha.GetAllClients(); // view all clients

                    break; // return to sub menu

            }
        }

            break; // return to main menu

        case 2:

        while (subIndex != 0){ // while user does not wish to return to main menu

            cout << "What would you like to do?" << endl; // prompt
            cout << "Modify sales rep (Enter: 1)" << endl; // options
            cout << "Add new sales rep (Enter: 2)" << endl;
            cout << "Get a sales rep's info (Enter: 3)" << endl;
            cout << "View sales reps (Enter: 4)" << endl;
            cout << "View a sales rep's bonus (Enter: 5)" << endl;
            cout << "Go back to main menu (Enter: 0)" << endl;

            cin >> subIndex; // user input for sub menu
            cin.ignore(); // ignore cin after sub index input

            switch(subIndex) { // options within department
                case 1:

                    beta.SetModifySalesRep(); // update a sales rep

                    break; // return to sub menu 

                case 2:

                    beta.SetNewSalesRep(); // add new sales rep

                    break; // return to sub menu

                case 3:

                    beta.GetSpecificSalesRepInfo(); // view specific sales rep's information

                    break; // return to sub menu

                case 4:

                    beta.GetAllSalesReps(); // view all sales reps

                    break; // return to sub menu

                case 5:

                    beta.SalesRepBonus(); // view a sales rep's bonus

                    break; // return to sub menu

            }
        }

            break; // return to main menu

        case 3:

        while (subIndex != 0) // while user does not wish to return to main menu
        {
            cout << "What would you like to do?" << endl; // prompt
            cout << "Modify product (Enter: 1)" << endl; // options
            cout << "Add new product (Enter: 2)" << endl;
            cout << "Get a product's info (Enter: 3)" << endl;
            cout << "View products (Enter: 4)" << endl;
            cout << "View product sales (Enter: 5)" << endl;
            cout << "Go back to main menu (Enter: 0)" << endl;

            cin >> subIndex; // user input for sub menu
            cin.ignore(); // ignore cin after sub index input

            switch (subIndex)
            {
            case 1:

                gamma.SetUpdateProduct(); // update product's information

                break; // return to sub menu

            case 2:

                gamma.SetNewProduct(); // add new product

                break; // return to sub menu 

            case 3:

                gamma.GetSpecificProductInfo(); // view specific product's informatioin

                break; // return to sub menu

            case 4:

                gamma.GetAllProduct(); // view all products

                break; // return to sub menu
            
            case 5:

                gamma.MonthlySalesReport(); // view monthly sales report

                break; // return to sub menu

            }
        }    

            break; // return to main menu

        case 4:

        while (subIndex != 0) // while user does not return to main menu
        {
            cout << "What would you like to do?" << endl; // prompt
            cout << "Purchase a product (Enter: 1)" << endl; // options
            cout << "View sales for the year (Enter: 2)" << endl;
            cout << "View sales for a specific client (Enter: 3)" << endl;
            cout << "Update client's sale (Enter: 4)" << endl;
            cout << "Go back to main menu (Enter: 0)" << endl;
            
            cin >> subIndex; // user input for sub menu
            cin.ignore(); // ignore cin after sub index input

            switch (subIndex)
            {
            case 1:

                delta.PurchaseProduct(); // purchase a product

                break; // return to sub menu
                
            case 2:

                delta.ViewAllSales(); // view sales

                break; // return to sub menu
            
            case 3:

                delta.ViewClientSales(); // view specific client sales

                break; // return to sub menu
            
            case 4:

                delta.UpdateClientSales(); // update client sales

                break; // return to sub menu

            }
        }

        break; // return to main menu
        
    }

    cout << "What is next?" << endl; // main menu return greeting
    cout << "Please select which department you would like to enter:" << endl; // department orientation
    cout << "Clients (Enter: 1)" << endl; // options
    cout << "Sales reps (Enter: 2)" << endl;
    cout << "Products (Enter: 3)" << endl;
    cout << "Sales (Enter: 4)" << endl;
    cout << "Quit (Enter: 0)" << endl; // exit index

    cin >> index; // user input
    cin.ignore(); // ignore cin after index input

    }

    cout << "Have a good day - thanks for stopping by Welding Central!" << endl; // farewell prompt

    return 0; // end main
}

any help would be appreciated

Answer 1

Clear out subindex in the outer loop. What is probably happening is that you get an index of 1 and do the first of the switch statements. You then get subindexes for a while until they hit 0, then you go back to the outer loop. Pick 2 this time.

But subindex already has a 0 in it, so the while loop exits right away.

This code would be a LOT safer if you made better use of functions. Each of the inner loops could be a separate function. That would eliminate variables drifting from one of the switch conditions to the next one the next time around. And the code would be more readable.