ここでいくつか変更することをお勧めします。オブジェクト指向設計に精通していますか? そうでない場合、C++ でコードを記述しようとしている場合は、それについて読むことを強くお勧めします (または、多くのプログラミング言語の非常に重要な側面であるため、一般的にコードを記述します)。
各メニューとサブメニューを個別のオブジェクトとして扱うことを検討してください。ループに入るたびに、オブジェクト ポインターを使用して、現在のメニュー テキストを出力するメソッドを呼び出します。
次に、通常どおりユーザーからの入力を受け取り、現在使用しているメニュー オブジェクトを変更します。
これは、コンソール メニューを実行するための最も理想的な方法ではないかもしれませんが、オブジェクト指向プログラミングがどのように機能するかについて非常に強力な基礎を築くことができます。
例を添付しました：
#include <iostream>
#include <string>
class BaseMenu
{
public:
BaseMenu() { m_MenuText = "This shouldn't ever be shown!"; } // This is the constructor - we use it to set class-specific information. Here, each menu object has its own menu text.
virtual ~BaseMenu() { } // This is the virtual destructor. It must be made virtual, else you get memory leaks - it's not a quick explaination, I recommend you read up on it
virtual BaseMenu *getNextMenu(int iChoice, bool& iIsQuitOptionSelected) = 0; // This is a 'pure virtual method', as shown by the "= 0". It means it doesn't do anything. It's used to set up the framework
virtual void printText() // This is made virtual, but doesn't *have* to be redefined. In the current code I have written, it is not redefined as we store the menu text as a string in the object
{
std::cout << m_MenuText << std::endl;
}
protected:
std::string m_MenuText; // This string will be shared by all children (i.e. derived) classes
};
class FirstMenu : public BaseMenu // We're saying that this FirstMenu class is a type of BaseMenu
{
FirstMenu()
{
m_MenuText = "Main Menu\n" // What we are doing here is setting up the string to be displayed later
+ "Please make your selection\n" // What we are doing here is setting up the string to be displayed later
+ "1 - Start game\n" // What we are doing here is setting up the string to be displayed later
+ "2 - Options\n" // What we are doing here is setting up the string to be displayed later
+ "3 - Quit\n" // What we are doing here is setting up the string to be displayed later
+ "Selection: "; // What we are doing here is setting up the string to be displayed later
}
BaseMenu *getNextMenu(int choice, bool& iIsQuitOptionSelected) // This is us actually defining the pure virtual method above
{
BaseMenu *aNewMenu = 0; // We're setting up the pointer here, but makin sure it's null (0)
switch (choice) // Notice - I have only done "options". You would obviously need to do this for all of your menus
{
case 2:
{
aNewMenu = new SecondMenu; // We're creating our new menu object here, and will send it back to the main function below
}
case 3:
{
// Ah, they selected quit! Update the bool we got as input
iIsQuitOptionSelected = true;
}
default:
{
// Do nothing - we won't change the menu
}
}
return aNewMenu; // Sending it back to the main function
}
};
class SecondMenu : public BaseMenu
{
SecondMenu()
{
m_MenuText = "OptionsMenu\n"
+ "Please make your selection\n"
+ "1 - ????"
+ "2 - dafuq?";
}
BaseMenu *getNextMenu(int choice, bool& iIsQuitOptionSelected) // This is us actually defining the pure virtual method above
{
BaseMenu *aNewMenu = 0; // We're setting up the pointer here, but makin sure it's null (0)
switch (choice) // Notice - I have only done options. You would obviously need to do this for all of your menus
{
case 1:
{
aNewMenu = new FirstMenu; // We're creating our new menu object here, and will send it back to the main function below
}
break;
case 2:
{
aNewMenu = new FirstMenu; // We're creating our new menu object here, and will send it back to the main function below
}
break;
default:
{
// Do nothing - we won't change the menu
}
}
return aNewMenu; // Sending it back to the main function
}
};
int main (int argc, char **argv)
{
BaseMenu* aCurrentMenu = new FirstMenu; // We have a pointer to our menu. We're using a pointer so we can change the menu seamlessly.
bool isQuitOptionSelected = false;
while (!isQuitOptionSelected) // We're saying that, as long as the quit option wasn't selected, we keep running
{
aCurrentMenu.printText(); // This will call the method of whichever MenuObject we're using, and print the text we want to display
int choice = 0; // Always initialise variables, unless you're 100% sure you don't want to.
cin >> choice;
BaseMenu* aNewMenuPointer = aBaseMenu.getNextMenu(choice, isQuitOptionSelected); // This will return a new object, of the type of the new menu we want. Also checks if quit was selected
if (aNewMenuPointer) // This is why we set the pointer to 0 when we were creating the new menu - if it's 0, we didn't create a new menu, so we will stick with the old one
{
delete aCurrentMenu; // We're doing this to clean up the old menu, and not leak memory.
aCurrentMenu = aNewMenuPointer; // We're updating the 'current menu' with the new menu we just created
}
}
return true;
}
これは、最初は少し複雑かもしれないことに注意してください。人々が投稿した他の回答を読むことを強くお勧めします。それを行う方法についていくつかのアプローチを提供する必要があり、基本的なものからより複雑なものまで、各変更を調べることができます。