Defining Global Variables Between Two .cpp Files

4
votes

How can I share/globalize a bool variable between A.cpp and B.cpp where neither of them does include the other ones .h file?? They have other joint header files but not each other's. Can I define the global variables inside those shared headers?

Thanks

2
c++global-variables
please search before write question. if you search your title in this site, you'll find the answer more easily. – Hossein Nasr
This hints at a bad design. If those two files are so unrelated, why are they sharing a single bool ? – MSalters

2 Answers

13
votes

Can I define the global variables inside those shared headers?

No.

In A.cpp (or) B.cpp write, 

int gVariable = 10;

Remember to write the above definition in only one source file or else linker will complain of multiple symbols if you write in both the source files.

And in the common header of A.cpp, B.cpp write,

extern int gVariable;
0
votes

file 1:

int x = 50;

file 2:

extern int x;