無法正確嵌套我的錯誤消息

Question

我無法在用戶輸入的值等於或小於零時正確地嵌套獲取錯誤消息。我不確定它應該去哪裏，或者如果我需要完全做其他事情。任何幫助，將不勝感激。以下是我的代碼。 「一個軟件公司銷售一個零售價爲99美元的軟件包，其數量折扣按照以下方式給出：」10-19 = 20％折扣，20-49 = 30％折扣，50-99 = 40 ％折扣，100+ = 50％折扣。 編寫一個程序，要求購買的單位數量並計算購買總成本。 輸入驗證：決定程序應該如何處理的輸入小於0

#include <iostream> 
#include <iomanip> // needed for setprecision 
#include <stdio.h> 

using namespace std; // need to use cout, cin, etc. 

int main() 
{ 
    double quantity, package = 99.00, initialPrice, discPrice, discount, calcDiscount, percent; // using double here because future multiplication by .2 

    cout << "This program will calculate how much of a discount you may receive,\nbased on how many software packages you buy.\n\n"; 
    cout << "How many software packages do you intend to purchase?\n\n"; 
    cin >> quantity; 

    { 
     if (quantity <= 0) 
      cout << "\nThat is not an acceptable amount. Please re-run the program with a amount greater than zero.\n\n"; 
    } 

    if (quantity >= 10 && quantity <= 19) 
     discount = 0.2, percent = 20; 
    else if (quantity >= 20 && quantity <= 49) 
     discount = 0.3, percent = 30; 
    else if (quantity >= 50 && quantity <= 99) 
     discount = 0.4, percent = 40; 
    else if (quantity >= 100) 
     discount = 0.5, percent = 50; 
    else if (quantity <10 && quantity >=1) 
     discount = 0, percent = 0; 

    { 
     initialPrice = package * quantity; 
     calcDiscount = (discount * package * quantity); 
     discPrice = initialPrice - calcDiscount; 
     cout << "\nThe total price for " << quantity << " software packages, minus a " << percent << "% discount of $"; 
     cout << fixed << showpoint << setprecision(2) << calcDiscount << ","; 
     cout << " is $" << fixed << showpoint << setprecision(2) << discPrice << ".\n\n"; 
    } 

    return 0; 
} 

Answer 1

您的代碼可以固定這樣的：

if (quantity <= 0) 
{ 
    cout << "\nThat is not an acceptable amount. Please re-run the program with a amount greater than zero.\n\n"; 
    return -1; 
} 
else if (quantity < 10) 
    discount = 0, percent = 0; 
else if (quantity < 20) 
    discount = 0.2, percent = 20; 
else if (quantity < 50) 
    discount = 0.3, percent = 30; 
else if (quantity < 100) 
    discount = 0.4, percent = 40; 
else discount = 0.5, percent = 50; 

initialPrice = package * quantity; 
calcDiscount = (discount * package * quantity); 
discPrice = initialPrice - calcDiscount; 
cout << "\nThe total price for " << quantity << " software packages, minus a " << percent << "% discount of $"; 
cout << fixed << showpoint << setprecision(2) << calcDiscount << ","; 
cout << " is $" << fixed << showpoint << setprecision(2) << discPrice << ".\n\n"; 

其他一些小的改動應使代碼的樣子更好 - 它對你