CareerCup

Keeps printing in a loop:

from a.h:<linenumber>,
from b.h:<linenumber>,
from a.h:<linenumber>,
from b.h:<linenumber>,
from b.h:<linenumber>,
a.h:<linenumber>: error: previous definition of 'class A'
....
.from a.h:<linenumber>,
from b.h:<linenumber>,
..goes on for sometime n stops

Thanks for posting these.

I'm surprised at their interview questions. No problem solving, all trivia.

The macro would be #ifndef (not #ifdef). Use #ifndef then #define #endif.
This would prevent multiple inclusions of your header file.

Good question. The programmer will end up with circular dependency. For example, if a.h contains structure A and a function void funA(A, B) and b.h contains structure B and a function void funB(A, B).

When these files are included in a source file, the compiler throws error, "one of the structure definition is not available". It is because none of the order "a.h followed by b.h" or "b.h followed by a.h" can provide the complete declaration of structures.

This can be solved by forward declaration of structures, passing references (pointers), strictly following top-down declaration across the common project files, etc...