Hi
conssider the following files:
head1.h :
head1.cpp :Code:#ifndef HEAD1_H #define HEAD1_H struct test { int a; } structTest; #endif
main.cpp :Code:#include "head1.h" int func() { return structTest.a; }
my problem is, when i try to compile this program it gives me a multiple definition of structTest. How can i prevent this??Code:#include <iostream> #include "head1.h" int main() { std::cout <<structTest.a; }
Your header file should contain this
Exactly ONE .cpp file should haveCode:struct test { int a; } extern test structTest;
It would be better if you didn't have this kind of global variable sharing.Code:test structTest;
If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
If at first you don't succeed, try writing your phone number on the exam paper.
tks that solved it
With your code, you get StructTest in head1.cpp and main.cpp. Both global. Hence linking error.
Salem's solution simply creates one global instance and refers the other files to use that instance instead.
Originally Posted by Adak
