while循环多个语句

Question

我对循环有一些问题。我正在尝试循环多个语句。代码如下。

int MenuSelect () {
    cout << endl;
    cout << YELLOW  << "Enter 1 for info" << endl;
    cout << " " << endl;
    cout << "Enter 2 to Start" << endl;
    cout << " " << endl;
    cout << "Enter 3 to view settings" << endl;
    cout << " " << endl;
    cout << "Enter 4 to quit" << endl;

     int selected = 0;
    string input;
    cin >> input;
    if (stringstream(input) >> selected) {
        return selected;
    }
    else {
        return -1;
    }

    return 0;

};    

int Menu(int) {

    int selected {};
    while ((selected = MenuSelect()) == 1) {

        printmessage();


    }
    if (selected == 3) {

        cout << "Current Settings" << endl;

        somefunction();
    }

    else if (selected == 2) {

        cout << "Starting Game..... " << endl;
    }

    else if (selected == 4) {

        cout << "Exiting....." << endl;
        exit (3);
    }

    else {

        cout << "Invalid Entry" << endl;
        exit (3);
    }

    cout << "Below is the Deck of cards and you will get to choose 5 cards to play with. Choose wisely." << endl;

    return 0;

};

因此，正如您所看到的，用户可以看到菜单，然后if和else语句将执行此工作。此时，我已经成功地循环第一个菜单，选择，所以如果用户输入1，它将打印消息，然后循环回到菜单。我想要的是也循环的3-当前设置，如果用户输入一个无效的数字。我试过了，但似乎做不到。

Answer 1

您可能希望重复读取用户输入并做出相应的反应？您可以将所有的if放入while中

int Menu(int) {

    int selected {};
    bool loop = true;

    while (loop) {
        selected = MenuSelect();

        if(selected == 1) {
            printmessage();
        }
        else if (selected == 3) {
            cout << "Current Settings" << endl;

            somefunction();
        }
        else if (selected == 2) {
            cout << "Starting Game..... " << endl;
        }
        else if (selected == 4) {
            cout << "Exiting....." << endl;
            loop = false;
        }
        else {
            cout << "Invalid Entry" << endl;
            loop = false;
        }
    }

    cout << "Below is the Deck of cards and you will get to choose 5 cards to play with. Choose wisely." << endl;

    return 0;

};

使用变量loop退出while只是个人喜好，您可能会有一个无限的循环

while(true)

然后使用break;退出循环，或者使用exit()退出整个程序，就像现在一样。