Using member function to solve equation C++ - c++

Question

I am currently trying to create a program to calculate the mass of a rocket with given time values by passing an array to a member function of a class. I get these two errors and can't seem to figure out how to get rid of them. Any suggestions are much appreciated, thank you.
23 8 [Error] prototype for 'double equip::calcmass(double)' does not match any in class 'equip'
13 10 [Error] candidate is: double equip::calcmass()
#include <iostream>
#include <fstream>
#include <cmath>
#include <cstring>
using namespace std;
class equip
{
public:
double mass[999999999], velocity, height, time[999999999];
double calcmass();
private:
double T = 7000;
double g = 32.2;
double K = 0.008;
};
double equip::calcmass(double time)
{
int i = 0;
for(i=0; i=999999999; i++)
{
return mass[i] = (3000 - 40 * time[i]) / g;
}
}
int main()
{
int i = 0;
equip rocket;
ifstream infile;
string filename;
cout<<"Enter input file name for time (time): ";
cin>>filename;
infile.open(filename.c_str());
while(infile.fail())
{
cerr<<"Error opening file. \n";
cout<<"Enter file name: ";
cin>>filename;
infile.open(filename.c_str());
}
for(i=0; i<999999999; i++)
{
infile>>rocket.time[i];
}
for(i=0; i<999999999; i++)
{
cout<<rocket.mass[i];
}
return 0;
}

Answer 1

In your class definition you've declared
double calcmass()
In the definition of the member function it's
double calcmass(double time)
They do not match. One takes a double as argument and the other does not.

Answer 2

You were missing a bunch of headers, and in the function declaration was missing the parameter presents in the function definition:
#include <cmath>
#include <cstring>
#include <fstream>
#include<iostream>
using namespace std;
class equip
{
public:
...
double calcmass(double time); // here was missing the parameter
...
};
double equip::calcmass(double time)
{
...
}
Also you are doing time[i] on time which is a double, so you can't use operator[]... If you want to pass an array, you can use pointer to double:
class equip{
...
double calcmass(double* time)
}
double equip::calcmass(double* time)
{
...
}