c++ - 如何循环这个程序

Question

所以我使用我在 YouTube 上关注的教程制作了这个简单的程序，但我没有看到的是如何让用户有机会提供新的选择，如果以前的选择无效。

程序如下:

#include <iostream>

using namespace std;

int main() {

    cout << "1. Search" << endl;
    cout << "2. Quit This Program" << endl;
    cout << "3. View Record" << endl;

    cout << "Enter Your Selection Please >   " << flush;

    int input;
    cin >> input;

    switch(input) {
    case 1:
        cout << "Searching..." << endl;
        break;

    case 2:
        cout << "Quitting This Program" << endl;
        break;

    case 3:
        cout << "Searching For Record For Viewing..." << endl;
        break;
    default:
        cout << "That is not a valid option" << endl;
        cout << "Please choose a selection from the menu:" << endl;
    }

    return 0;


} 

Answer 1

需要一个循环来检查选择是否有效，如果有效则跳出循环，如果无效则继续循环直到有效。

#include <iostream>

    using namespace std;

    int main() {
        bool selection = false;
        while(!selection){
            cout << "1. Search" << endl;
            cout << "2. Quit This Program" << endl;
            cout << "3. View Record" << endl;

            cout << "Enter Your Selection Please >   " << flush;


            int input;
            cin >> input;

            switch(input) {
            case 1:
                cout << "Searching..." << endl;
                selection = true;
                break;

            case 2:
                cout << "Quitting This Program" << endl;
                selection = true;
                break;

            case 3:
                cout << "Searching For Record For Viewing..." << endl;
                selection = true;
                break;
            default:
                cout << "That is not a valid option" << endl;
                cout << "Please choose a selection from the menu:" << endl;
            }
        }

        return 0;


    }