从函数中返回某些变量？

Question

在过去的几个小时里，我在学习了星期五的功能后，一直在研究这个程序，而且我不确定如何从我的函数中调用特定的变量。在下面的代码中，我需要调用我在cash（）函数中计算的值，这些是;数百，五十，二十，几十，五，toonies和loonies。谢谢。我的问题是如何从我的函数调用特定值，下面的代码不起作用。

int main()
{
//DECLARATIONS
int totalDollarAmount;
int hundreds = 0;
int fifties = 0;
int twenties = 0;
int tens = 0;
int fives = 0;
int loonies = 0;
int toonies = 0;

 //prompt for input
cout << "Please input a dollar amount: " << totalDollarAmount << endl;

hundreds = cash(hundreds);
hundreds = cash(fifties);
hundreds = cash(twenties);
hundreds = cash(tens);
hundreds = cash(fives);
hundreds = cash(toonies);
hundreds = cash(loonies);

cout << " The total number of Fifties is: " << fifties << endl;
cout << "The total number of Twenties is: " << twenties << endl;
cout << "The total number of Tens is: " << tens << endl;
cout << "The total number of Fives is: " << fives << endl;
cout << "The total number of Toonies is: " << toonies << endl;
cout << "The total number of Loonies is: " << loonies << endl;
return 0;
}//end main

//code function
int cash(int hundreds, int fifties, int twenties, int tens, int fives, int loonies, int toonies, int totalDollarAmount)
{
totalDollarAmount * 100;

hundreds = totalDollarAmount/10000;
totalDollarAmount = totalDollarAmount % 10000;

fifties = totalDollarAmount/5000;
totalDollarAmount = totalDollarAmount % 5000;

twenties = totalDollarAmount/2000;
totalDollarAmount = totalDollarAmount % 2000;

tens = totalDollarAmount/1000;
totalDollarAmount = totalDollarAmount % 1000;

fives = totalDollarAmount/500;
totalDollarAmount= totalDollarAmount % 500;

toonies = totalDollarAmount/200;
totalDollarAmount = totalDollarAmount % 200;

loonies = totalDollarAmount/100;
totalDollarAmount = totalDollarAmount % 100;
}//end function

Answer 1

您的代码存在一些问题。

1. 您的cash函数接受8个参数，而您在每个函数调用中只传递一个参数。
2. 您的cash函数返回int，但在函数内部您没有返回任何内容。
3. 如果要从一个函数调用返回许多值，可以使用结构或类并返回其值，否则需要通过引用或指针传递参数。
4. 您使用错误的命令向变量输入值。使用cin输入值而不是cout。

对代码进行一次快速修复可能就像将cash功能更改为

一样

void cash(int &hundreds, int &fifties, int &twenties, int &tens, int &fives, int &loonies, int &toonies, int &totalDollarAmount)

然后在main函数中，执行以下更改：

1. 将输入提示更改为

   cout << "Please input a dollar amount: ";
   cin >> totalDollarAmount;
   

2. 将调用的函数更改为

   cash(hundreds, fifties, twenties, tens, fives, loonies, toonies, totalDollarAmount);
   

P.S。您的cash函数中可能仍存在一些逻辑问题，例如您从未分配给变量的第一行totalDollarAmount * 100;。但是那些程序逻辑我会留给你解决。