extern keyword in c

Question

Possible Duplicate:
Why do we need extern “C”{ #include <foo.h> } in C++?

many a times in our code i have seen some statements like following:

extern "C" {

//some code

        };

what does this exactly mean?

possible duplicate of (or rather, covered by) [Why do we need extern "C"{ #include } in C++?](http://stackoverflow.com/questions/67894/why-do-we-need-extern-c-include-foo-h-in-c) — , Mar 28 '11 at 17:27

score 1 · Answer 1 · answered Mar 28 '11 at 17:28

1

It tells the C++ compiler that "some code" must be compiled in C style. This allows the linkage between C and C++ code.

answered Mar 28 '11 at 17:28

Thiago Cardoso

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score 1 · Answer 2 · answered Mar 28 '11 at 17:29

1

It tells the compiler to treat the following code as C code and not as c++ code

answered Mar 28 '11 at 17:29

AsiQue

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score 0 · Answer 3 · answered Mar 28 '11 at 17:30

More to the point, functions with C++ linkage will not be found by the linker when called from a C function unless you specify that the functions should have the same linkage type. So you'll get all sorts of link errors, which won't seem obvious as to why.

extern keyword in c

3 Answers3