Console Application Menu with Classes C++

Question

I am currently working on a personal project in C++, and I'm having a lot of fun learning. I just learned some ideas on using inheritance and virtual functions. I decided to create a Budget Tracking console application! Of course, I could use control statements, and switches; however, I wanted to try and solve this using classes. Here is my code so far: Main.cpp #include #include "MainMenu.h" #include "Menu.h" int main() { std::cout << "Welcome to BudgetTracker!\n" << "Let's get started!\n\n"; Menu *menu = new MainMenu; int mainInput; menu->displayMenu(); std::cin >> mainInput; menu->input(mainInput); //Somehow switch my menu to a sub menu //Add a loop without terminating entirely } MainMenu.cpp #include "MainMenu.h" MainMenu::MainMenu(){} MainMenu::~MainMenu(){} void MainMenu::displayMenu() { std::cout << "Welcome to the MainMenu! \n" << "Select an option from the following: \n" << "1.....Overall View\n" << "2.....Accounts\n" << "3.....Spending\n" << "4.....Statistics\n" << "5.....Budgeting\n" << "0.....Close Program\n\n"; } void MainMenu::input(int userInput) { m_input = userInput; std::cout << "You have entered " << m_input << ".\n\n"; //some code to enter a different submenu } In the end, I imagine a user entering, something along the lines of while in mainMenu -> input 2. Now in accountMenu -> input 3 to manage accounts. Input 2-> add account. Can you guys help me find a way to implement this idea? I saw something in regards to a composite pattern design; however, I felt as though it doesn't match this idea. Am I wrong? Is this a wrong approach? Thanks in advance! JavaScript questions and answers, JavaScript questions pdf, JavaScript question bank, JavaScript questions and answers pdf, mcq on JavaScript pdf, JavaScript questions and solutions, JavaScript mcq Test , Interview JavaScript questions, JavaScript Questions for Interview, JavaScript MCQ (Multiple Choice Questions)

Answer 1

For menus, I recommend using state tables (data driven software): // Define short hand for function pointer typedef void (*Menu_Processing_Function_Ptr)(); struct Menu_Item { unsigned int number; const char * text; Menu_Processing_Function_Ptr p_processing_function; }; Given the above menu item structure, you can create a generic engine that processes {any} menu. A menu would be an array of Menu_Item. void Menu_Engine(Menu_Item * p_menu, unsigned int item_quantity) { // Display the menu for (unsigned int i = 0; i < item_quantity; ++i) { std::cout << p_menu[i].number << ". " << p_menu[i].text << "\n"; } std::cout << "Enter selection: "; unsigned int selection; std::cin >> selection; for (unsigned int i = 0; i < item_quantity; ++i) { if (selection == p_menu[i].number) { // Execute the processing function for the selection. (p_menu[i].p_processing_function)(); break; } } if (i >= item_quantity) { std::cout << "invalid selection\n"; } } You can then define a menu as: // Forward declarations void Process_Selection_1(); void Process_Selection_2(); void Process_Selection_3(); Menu_Item first_menu[] = { {1, "First Selection", Process_Selection_1}, {2, "Second Selection", Process_Selection_2}, {3, "Third Selection", Process_Selection_3}, }; static const unsigned int menu_size = sizeof(first_menu) / sizeof(first_menu[0]); An example usage: int main() { // Process the menu Menu_Engine(&first_menu[0]); // Pause. std::cout << "Paused. Press ENTER to continue."; std::cin.ignore(1000000, '\n'); return 0; } This pattern allows you to change the menu without having to retest or change the code (the engine). Adding a selection or modifying a selection does not affect the engine. This allows for the menu to be placed into read-only memory. You will only need one engine to process multiple menus. Edit 1: std::map Another possibility is to use an associative array, mapping the selection number to the selection attributes: struct Menu_Item_Attributes { const char * text; Menu_Processing_Function_Ptr p_processing_function; }; typedef std::map<unsigned int, Menu_Item_Attributes> Menu_Item_Container; Your input processing would be: unsigned int selection; std::cout << "Enter selection: "; std::cin >> selection; try { Menu_Item_Attributes attributes = menu.at(selection); (attributes.p_processing_function)(); } catch (std::out_of_range& e) { std::cout << "Invalid selection"; } Reminder that the std::map cannot be stored in read-only memory and would need to be initialized during run-time.