CODEWITHSUNDEEP
c++visual-c++global-variablesextern
codeLover
codeLover

Reputation: 3810

Access a variable declared in one file in anothe file in VC++. (Extern keyword usage)

I have a VC++ solution (using VS2008) with 2 projects Project A & project B.

Everything I discuss below is wrt Project A.

Project A has a sourec file a.cpp & it includes a header file "a.h". "a.h" has a variable int varA; which is modifies inside a.cpp. 

a.cpp:
int varA = x*2;
// also do some calculations with varA in a.cpp

Now there is one more sourec file b.cpp in the same project A. And now lets say this "b.cpp" also includes same header file "a.h". i.e

b.cpp
int varB = varA; // If I want to access varA & get the current value of varA here in b.cpp what should do ? Will it work if I declare varA as extern in a.h & include

Here it's important to note that I wnat to not only access the variable varA from within b.cpp but also want to access the current value of this variable as updated by a.cpp.

Thnaks in advance.

Upvotes: 0

Views: 176

Answers (2)

Sudhakar B
Sudhakar B

Reputation: 1563

Create a header file A.h

extern int varA;

In A.cpp declare variable 

int varA;

Include "A.h" in b.cpp

That's it.

Upvotes: 2

Paskas
Paskas

Reputation: 2848

Declare variable in some header file and then include this header to cpp file where you want to use it.

Upvotes: 0

Related Questions