Would someone please explain how to place a function in my main.ccp file in the c++ language?

Question

So far I've written this,

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

int main()
{
    double pi;
    pi = ( asin(1)*2 );
    cout << " The value of pi is: " << pi << setprecision(pi) << endl;
}

But I need to place this function in my main.ccp file, place code in my main function to call my pi() function and store the returned value in a variable.  Then using cout, display the value, as well as the value of M_PI to the console for comparison purposes.

I was forced to miss lecture this day and now as a result I'm now completely confused regarding what this is even asking for, so any help would be greatly appreciated!

Answer 1

An example function is at this link http://www.cplusplus.com/doc/tutorial/functions/

You add the function to the main.cpp file.

E.g.

...

int main(){

double my_pi;
my_pi=pi();
cout goes here...
}

// This is the function
double pi(){
     return asin(1)*2;
}

Also read the example http://www.cplusplus.com/reference/iomanip/setprecision/ how setprecision is used.

Answer 2

Treat main as a function:
- You have no parameters in the () after main.
- You have to return an integer at the end of the function, though most compilers will automatically  return a value for main so you dont need to.

Essentially, just write the function like this:

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

int setprecision(int pi);

int main()
{
    double pi;
    pi = ( asin(1)*2 );
    cout << " The value of pi is: " << pi << setprecision(pi) << endl;
}

int setprecision()
{
    return pi;
}

--
Of course, you'll need to change the code according  to want you want. For more information, check out: http://learn.onlinegdb.com/c%2B%2B_functions

Comments

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

int setprecision(int pi);

int main()
{
    double pi;
    pi = ( asin(1)*2 );
    cout << " The value of pi is: " << pi << endl;
}

int setprecision(int pi)
{
    return pi;
}