Question

所以我在打印所有内容时遇到了问题。应该是“您有优惠券吗？”然后，“是成人票还是儿童票的折扣？”然后根据答案输入错误代码或进入收据。仅当用户在“您有折扣券吗？”中回答“是”时，折扣才弹出。部分。但是我无法使其与if和else语句一起使用。

起初，我尝试将所有的if和else语句放在一起，但打印顺序不正确。因此，现在我尝试在中间插入收据，但这使if语句的操作混乱，并且收据显示不正确。无论我输入C还是A（稍后都会声明这两个字符，并且不应该提示打印错误消息），都会打印错误消息。折扣仍然适用，但错误消息不应打印。

cout<< "\nDo you have a discount coupon (Y for yes)? ";                             
cin>> haveDiscount;

if (haveDiscount == "Y")
{
    cout<< "\nIs the discount for an adult or child's ticket (A for adult, C for child)? ";
    cin>> discountType;
}
if (haveDiscount == "N")
{
    cout<< endl;
}
else
{
    cout<< "\nError: ";
    cout<< discountType;
    cout<<" is not a valid discount type. No discount will be applied.";
}

cout<< "\n\n************************************" << endl;
cout<< right << setw(22) << "Theater Sale";
cout<< "\n************************************";                                            
cout<< "\n\nNumber of adult tickets: " << setw(11) << adultTickets;                         
cout<< "\nNumber of child tickets: " << setw(11) << childTickets << endl;

if (discountType == "A")
{
    coupon = 11.25;
    cout<< "\nDiscount: " << setw(26) << coupon << endl;
}
else
{
    if (discountType == "C")
    {
        coupon = 4.50;
        cout<< "\nDiscount: " << setw(26) << coupon << endl;
    }
}

total = (adultPrice * adultTickets) + (childPrice * childTickets) - coupon;
cout<< "\nTotal purchase: " << setw(20) << total;

我需要输入C或A（声明为折扣）时不打印错误消息，并且仅在其他情况下打印。

Answer 1

如果您缩进代码，则阅读起来会容易得多。看来您缺少了一些假设。现在看起来像这样：

if (haveDiscount == "Y") 
{
   // ask next question
}
if (haveDiscount == "N") 
{
   // print new line
} 
else 
{
   // print error
}

这意味着无论他们有什么折扣，它都将打印错误。如果haveDiscount不等于“ N”，则会显示错误-如果他们对第一个问题回答“ Y”，则该错误将始终为true。您可能想要更多类似这样的东西：

if (haveDiscount == "Y") 
{
   // ask next question
   if (discountType == "C" || discountType == "A")
   {
      // do something
   }
   else 
   {
      // print error
   }
}
else 
{
   // print new line
}

Answer 2

在discountType不是C或A的情况下打印错误看起来像

if (discountType == "A") 
{
    coupon = 11.25; cout<< "\nDiscount: " << setw(26) << coupon << endl; 
}
else if (discountType == "C")
{
    coupon = 4.50; cout<< "\nDiscount: " << setw(26) << coupon << endl;
}
else
{
    cout<< "\nError: ";
    cout<< discountType;
    cout<<" is not a valid discount type. No discount will be applied."; }
}

如果您想在收据前打印错误，则可以

if (discountType != "C" || discountType != "A")
{
    // Error message
}

设置了discountType之后的某处。

不应在其他语句中输出输出

2 个答案: