Functions and return type

Question

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

class c1
{ public:
void fn(int a)
{
no=a;
};
private:
int no;
};
int main()
{
c1 obj;
obj.fn(10);
return 0;
}
In this program when can i replace return type of main function with void and remove return 0, and does returning integer type have something to do with the function fn's parameter as int?

Answer 1

Not 100% sure on the first point, I think C/C++ use int main but the main method in Java, for instance, is void main. Just the way it is :)
The return type is distinct from the parameter type, basically these define what comes out (return type) and what goes into the function (parameter type)

Answer 2

Dan Walker yea I haven't seen much void main in c++ unlike in java so I'll go with it, thanks 👍