Question

#include <iostream>
#include <strings.h>

using namespace std;

void encyclopedia()
{
int choice;
int choice2;

system("CLS");
cout << "Content Menu\n\n" 
     << "1. Gore\n\n"
     << "2. Wilson\n\n"
     << "3. Costa\n\n"
     << "Selection: ";
cin >> choice;
if (choice == 1)
{
           system("CLS");
           cout << "Al Gore's Book Summary of:\n\n"
                << "1. Introduction\n\n"
                << "2. \n\n"
                << "3. \n\n";
           cin >> choice2;
           if (choice2 == 1)
           {
                       system("CLS");
                      cout << "text here\n\n";
                      cout << "Press enter to continue\n";
                      cin.get();
                      encyclopedia();               
           }
           else if (choice2 == 2)
           {
                system("CLS");
                      cout << "text here\n\n";
                      cout << "Press enter to continue\n";
                      cin.get();
                      encyclopedia();               
           }
           else if (choice2 == 3)
           {
                system("CLS");
                      cout << "text here\n\n";
                      cout << "Press enter to continue\n";
                      cin.get();
                      encyclopedia();               
           }  
}
if (choice == 2)
{
           system("CLS");
           cout << "Wilson's Book Summary of:\n\n"
                << "1. Introduction\n\n"
                << "2. \n\n"
                << "3. \n\n";
           cin >> choice2;
           if (choice2 == 1)
           {
                       system("CLS");
                      cout << "text here\n\n";
                      cout << "Press enter to continue\n";
                      cin.get();
                      encyclopedia();               
           }
           else if (choice2 == 2)
           {
                system("CLS");
                      cout << "text here\n\n";
                      cout << "Press enter to continue\n";
                      cin.get();
                      encyclopedia();               
           }
           else if (choice2 == 3)
           {
                system("CLS");
                      cout << "text here\n\n";
                      cout << "Press enter to continue\n";
                      cin.get();
                      encyclopedia();               
           }  
}
if (choice == 3)
{
           system("CLS");
           cout << "Rebeca Costa's Book Summary of:\n\n"
                << "1. Introduction\n\n"
                << "2. \n\n"
                << "3. \n\n";
           cin >> choice;
           if (choice2 == 1)
           {
                       system("CLS");
                       cout << "text here\n\n";
                       cout << "Press enter to continue\n";
                       cin.get();
                       encyclopedia();               
           }
           else if (choice2 == 2)
           {
                       system("CLS");
                       cout << "text here\n\n";
                       cout << "Press enter to continue\n";
                       cin.get();
                       encyclopedia();               
           }
           else if (choice2 == 3)
           {
                      system("CLS");
                      cout << "text here\n\n";
                      cout << "Press enter to continue\n";
                      cin.get();
                      encyclopedia();               
           }  
}
}

int main()
{
cout << "2013 Written Task #2\n\nBy: Skye Leis\n\n";
cout << "Press enter to continue\n";
cin.get();
encyclopedia();   
}

当我的第一个cin.get（）工作时，我无法在我的百科全书（）之前获得cin.get（）。当它运行时，第一个屏幕工作，然后内容菜单工作，子菜单工作，但在显示实际文本的部分，它不会在重新启动百科全书功能之前等待输入键。

Answer 1

cin适用于格式化输入。这意味着它会在找到空格或新行之前进行读取。

问题在于你做什么

cin >> choice2;

当您输入数字并按Enter键时，cin将读取到blank space。这意味着newline（来自键enter）仍在那里。您的cin.get会读取该换行符并继续。

此外，如果我输入两个以空格分隔的数字，您的实现将采用第二个数字并将其用于下一个菜单输入。

为了确保在继续下一个菜单项之前读取输入上的任何内容，您可以使用getline()

string garbage;
cin >> choice2;
getline(cin, garbage);  // The will take care of any extra inputs.

Answer 2

会发生什么事情仍有剩余部分（终结点），因此您可能会在用户输入后获得其他一些不需要的字符，请尝试添加：

cin.ignore( numeric_limits <streamsize> ::max(), '\n' );

cin之后

Answer 3

它读取最后一个/ n 并做：

cin.clear（）; cin.get（）;

或者只写cin.get（）;两次

Cin.get（）第二次不使用它

3 个答案: