Linker Error - Multiple Definition

[icewizard]

I have a very simple question. I am trying to link the following 2 files, but I get an error saying "multiple definition of function()"

In a.cpp

int function(){
return 1;
}

In main.cpp

#include "a.cpp"
int main(){
return 0;
}

I know I can fix the error by making a header file for a.cpp, or putting function() inside a class, but I'm wondering what is causing this error, since I only defined function() once. Thanks.

[vijayan121]

> since I only defined function() once.
you defined it twice. once in a.cpp and once in main.cpp (which includes a.cpp)

[icewizard]

Oh ok, are there any simpler ways to fix this problem than making a separate header file or putting all the functions in a.cpp inside a class. And, I don't want to just put everything in my main.cpp file.
Thanks.

[John A]

The best method is just to make a header file for every source file. Source files aren't really supposed to be #include'd anyway, for the very reason you had your error.