C++ 控制台不显示菜单

Question

如果用户选择 1 或 2，函数不会运行。有什么建议吗？

#include <iostream>
using namespace std;

void getTitle();
void getIsbn();

int main()
{
    int choice = 0;      // Stores user's menu choice

    do
    {
        // Display menu
        cout << "             Main Menu\n\n\n";

        // Display menu items
        cout << "   1. Choose 1 to enter Title.\n";
        cout << "   2. Choose 2 to enter ISBN.\n";
        cout << "   3. Choose 3 to exit.\n";

        // Display prompt and get user's choice
        cout << "   Enter your choice: ";
        cin  >> choice;

        // Validate user's entry
        while (choice < 1 || choice > 3)
        {
            cout << "\n   Please enter a number in the range 1 - 3. ";
            cin  >> choice;
        }

        switch (choice)
        {
        case 1:
            getTitle();
            break;
        case 2:
            getIsbn();
            break;
        }
    } while (choice != 3);

    return 0;
}

void getTitle()
{
    string title;
    cout << "\nEnter a title: ";
    getline(cin, title);
    cout << "\nTitle is " << title << "\n\n\n";
}

void getIsbn()
{
    string isbn;
    cout << "\nEnter an ISBN: ";
    getline(cin, isbn);
    cout << "\nISBN is " << isbn << "\n\n\n";
}

Answer 1

当然应该调用函数。但是，当您按“Enter”键键入数字时生成的换行符将由 getline() 返回，并且该函数将在没有真正提示您的情况下返回。您需要清除该换行符。您可以使用 ignore() 来执行此操作:在 choice 中阅读后立即添加 cin.ignore(); 以忽略一个字符。