我事先表示歉意，因为我找不到我要提出的问题的更好用词，所以我不妨在这里解释一下。我最近得到了《 C++ How to program》第9版书，我一直在练习，我正处于第5章。我的问题是，在我的代码中，我在while循环中无法将总数添加到另一个变量中。基本上我每次都返回0，我也不知道我做错了什么。有人愿意说明情况并向我解释下一次我可以做得更好吗？我的意思是代码本身运行正常，没有错误，但是我在计算时遇到了麻烦!
#include <iostream>
#include <iomanip>
using namespace std;
void main()
{
int selection = 0;
float total = 0.0;
float lastTotal = 0.0;
float product1 = 2.98;
float product2 = 4.50;
float product3 = 9.98;
float product4 = 4.49;
float product5 = 6.87;
bool loop = true;
while (loop == true)
{
cout << "Please make a selection from the following items and when you are done buying (-1) the products I will display your total\n" << endl;
cout << "1: $" << product1 << endl;
cout << "2: $" << product2 << endl;
cout << "3: $" << product3 << endl;
cout << "4: $" << product4 << endl;
cout << "5: $" << product5 << endl << endl;
total += lastTotal;
cin >> selection;
cout << "\n";
switch (selection)
{
case 1:
cout << "You have selected Product 1 which costs $2.98\n" << endl;
total = product1;
break;
case 2:
cout << "You have selected Product 2 which costs $4.50\n" << endl;
total = product2;
break;
case 3:
cout << "You have selected Product 3 which costs $9.98\n" << endl;
total = product3;
break;
case 4:
cout << "You have selected Product 4 which costs $4.49\n" << endl;
total = product4;
break;
case 5:
cout << "You have selected Product 5 which costs $6.87\n" << endl;
total = product5;
break;
case -1:
cout << "Thank you. Your total is: " << lastTotal << endl;
loop = false;
break;
default:
cout << "Invalid selection" << endl;
}
}
}
错误:
prog.cpp:6:11: error: '::main' must return 'int'
void main()
^
也作为旁注。警告的确切含义是什么？我看不到他们使我的代码崩溃，但是当我在运行它们时弹出它们时，这与我有关。
最佳答案
您不需要使用lastTotal和total。仅使用总计即可完成工作。 lastTotal从未分配或更改!
cout << "Thank you. Your total is: " << lastTotal << endl;
改成:
cout << "Thank you. Your total is: " << total << endl;
总体还可以。但您显示的是lastTotal。
对于错误，将代码修改如下:
int main()
{
....
return 0;
}
主要必须是int!