c++ - 调用的对象类型 'double' 不是 report() 函数的函数或函数指针

Question

我正在尝试创建一个程序，该程序将在用户输入商品的批发和加价百分比时计算零售价。我确定除了第 15 行“double report = report(retailPrice)”之外的所有内容都是正确的，它给出了错误 called object type 'double' is not a function or function pointer for a report() function.

我尝试重命名几乎所有的报告变量，甚至将函数重命名为不同的东西，但它仍然会导致完全相同的错误。当完全省略 report() 函数并将其替换为 main() 中的 cout 语句时，它似乎工作正常，但不幸的是，无论它多么毫无意义，赋值都需要它。

#include <iostream>
#include <iomanip>
using namespace std;

double getWholeSale();
double getMarkup();
double calculateRetail(double, double);
double report();

int main()
{
    double wholeSale = getWholeSale();
    double markup = getMarkup();
    double retailPrice = calculateRetail(markup, wholeSale);
    double report = report(retailPrice);
    cout << report;

    return 0;
}
//**************************
double getWholeSale()
{
    double wholeSale;
    cout << "Enter the item's wholesale: ";
    cin >> wholeSale;
    while (wholeSale < 0)
    {
        cout << "Wholesale must be a positive number: ";
        cin >> wholeSale;
    }
    return wholeSale;
}
//**************************
double getMarkup()
{
    double markup;
    cout << "Enter the item's markup percentage: ";
    cin >> markup;
    while (markup < 0)
    {
        cout << "Markup percentage must be a positive number: ";
        cin >> markup;
    }
    return markup;
}
//*************************
double calculateRetail(double markup, double wholeSale)
{
    double retailPrice;
    double markupPercentage = markup / 100;
    retailPrice = (wholeSale * markupPercentage) + wholeSale;
    return retailPrice;
}
//*************************
double report(double retailPrice)
{
    cout << "The retail price is: $" << fixed << showpoint << setprecision(2) << retailPrice;
}

Answer 1

你像这样调用report:

double report = report(retailPrice);

你像这样实现report:

double report(double retailPrice)

但是你像这样声明report:

double report();

其中一个与其他不同 ;) 修改您的声明以包含 double 参数。