Main function already defined in visual studio project

Question

I created windows console program project in visual studio, and made two c language files. Both has same source:

#include<stdio.h>

int main() {
    printf("hello");
}

When I try to compile, compiler screams about having two main()s. See below:

I can't understand. I thought two files in one project works separately. Am I wrong?

Answer 1

Yes, you are wrong. IIRC, the whole project is compiled and then linked to form a single executable.

In a single executable, there can be only one main() function.