Question

所以我试图设置一个while循环来继续询问（y / n），但是当我按下'y'然后输入它跳过“char itemtitle”并直接进入“double itemprice”时怎么样？我是c +的新手，请帮忙，我会感激它

#include <cstdlib>
#include <iostream>
#include <sstream>

using namespace std;

#define tax 9.99
#define shipping ("Free")

void printmessage ()
{
  cout << "*Thanks for your business! We'll ship out your item as soon as possible*\n"
              "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n\n";
}

int main(int argc, char** argv)
{

   cout << "Write an invoice program and print it to the console.\n";
   cout << "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n\n;

   cout << "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n"
           "Welcome to my Pc Store.\n"
           "'Where Technology is served right'\n"
           "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n"<< endl;

   char name [256];
   cout << "Enter your full name: ";
   cin.getline (name, 256);

   char organization [256];
   cout << "What's your organization?: ";
   cin.getline (organization, 256);

   char quit = 'y';    
   do {
        char itemtitle [256];
        cout << "Enter name of Laptop you'd like to order: ";
        cin.getline (itemtitle, 256);

        double itemprice;
        cout << "Enter price of item: $";
        cin >> itemprice; 

        int quantity;
        quantity = 1;
        cout << "How many items?: ";
        cin >> quantity;

        if (quantity == 1) {     
            cout << "1 item(s)\n";  
        } else  {
           cout << quantity << " item(s)\n";
        } 

        cout << "Tax: $" << tax;

        double subtotal;
        subtotal = quantity * itemprice + tax;
        cout << "\nSub Total: $" << subtotal;

        cout << "\n";       
        cout << "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n\n"
               "Validation:\n\n";

        cout << "Item(s):\t\t\t\t\t" << "Amount:\n";       
        cout << itemtitle << "\t\t\t\t\t$" << quantity * itemprice + tax; ;
        cout << "\n" << quantity << " * $" << itemprice << " + $" << tax;

        cout << "\n~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n\n";
        cout << "Payment (Credit/Debit only)!\n\n";

        double cardnum;
        cout << "Card Numbers: ";
        cin >> cardnum;

        int ssn;
        cout << "SSN: ";
        cin >> ssn;

        cout << "\n~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n"
               "Invoice Details:\n\n";

        time_t rawtime;
        struct tm * timeinfo;
        time ( &rawtime );
        timeinfo = localtime ( &rawtime );
        cout << "Date&Time: " << ("Current local time and date: %s", asctime (timeinfo));

        cout << name;
        cout << "\n" << organization;
        cout << "\n" << "("<< quantity << ")" << " " << itemtitle;

        cout << "\n\t\t\t" << "Total: $" << quantity * itemprice;
        cout << "\n\t\t\t" << "Tax: $" << tax;
        cout << "\n\t\t\t" << "Shipping: " << shipping;
        cout << "\n\n\t\t\t" << "Balance Due: $" << quantity * itemprice + tax;

        cout << "\n\t\t\t" << "Payment: " << "Paid" ;

        cout << "\n\n\nDo you want to continue shopping? (y/n): ";
        cin >> quit ;

        cout << "\n\n";

    } while (quit != 'n');

    cout << "\n\n\n";
    printmessage ();

    return 0;
}

Answer 1

std::cin.operator>>()将'\n'字符留在缓冲区中，使getline几乎无法使用它。您必须选择其中一个，然后相应地更改代码。

例如，仅使用getline，然后解析结果字符串。

Answer 2

当你同时使用“cin＆gt;＆gt;”时和“cin.getline（）”从用户输入读取，你将主要遇到这个问题。似乎在使用“＆gt;＆gt;”时运算符，在读取输入后，'\ n'留在输入流中，这导致后续调用“getline”立即返回。

两种解决方案。

首先，添加“cin.ignore（）;”在“cin.getline（itemtitle，256）;”之前。 “cin.ignore（）”从输入序列中提取字符并丢弃它们。它将清除输入流。

其次，替换“cin.getline（itemtitle，256）;”使用“cin＆gt;＆gt; itemtitle;”。我建议使用“cin.getline”或“cin＆gt;＆gt;”在您的代码中，但不要同时使用它们。 “cin＆gt;＆gt;”会更好。

此外，应该加上“#include＆lt; ctime＆gt;”在代码的顶部。

怎么来循环跳过char？

2 个答案: