c++ - 无法调用函数

Question

我正在编写处理调用函数的代码。我大约进行了一半，当我尝试编译时出现错误“函数‘double()’的参数太多。” 这是我的代码。任何反馈都会有所帮助。

#include <iostream>
#include <cstdlib>

using namespace std;

void displayMenu();
double force();

int main(int argc, char** argv) 
{
    int menuOption;
    displayMenu();
    system("PAUSE");
    return 0;
}

void displayMenu(void)
{
    int menuOption;
    double weight;
    cout << "           Main Menu" << endl;
    cout << "Enter 1 for Force calculation with acceleration = 9.8m/s^2.\n";
    cout << "Enter 2 for Force calculation with user defined acceleration.\n";
    cout << "Enter 3 to quit the program.\n";
    cin >> menuOption;
        if(menuOption==1)
            cout << "Enter a mass.\n";
            cin >> weight;
            cout << force(weight);  
}

double force(double weight)
{
    double force, mass;
    force=(mass*9.8);
    return force;
}

Answer 1

将 double force(); 更改为 double force(double);