c++ - Is extern "C" required also for linking global variables used in Cpp file to the one defined in a cfile?

Question

Is extern "C" required also for linking global variables used in Cpp file to the one defined in a c file?

It is used for linking function from C++ file which is referenced in C file because of the name mangling of function names in C++ files. Does the C compiler also changes the name of variables??

Answer 1

Is extern "C" required also for linking global variables used in Cpp file to the one defined in a c file?

Portably, yes.

You might find that leaving out extern "C" works for your compiler (for example, GCC, which doesn't mangle C++ variable names in the global namespace), but that's not something you can rely on for all compilers.

Does the C compiler also changes the name of variables??

It depends on the compiler (specifically, on the ABI it uses). The language standards don't specify how language-level names map to linker symbols, so different compilers can use different name-mangling schemes.