I have a static variable in the class. I am Initializing that in the global scope, its works fine.
But When I try to Initialize in the main linker throws an error. Why it so.
class Myclass{
static int iCount;
} ;
int main(){
int Myclass::iCount=1;
}
And In global scope why I have to specify the variable type like
int Myclass::iCount=1;
As In my class I am definig iCount as integer type why not.
Myclass::iCount =1 ; in //Global scope
The section $9.4.2/7 from the C++ Standard says,
Static data members are initialized and destroyed exactly like non-local objects (3.6.2, 3.6.3).
Note the phrases "initialized" and "exactly like non-local objects". Hope that explains why you cannot do that.
In fact, static members are more like global objects accessed through Myclass::iCount. So, you've to initialize them at global scope (the same scope at which class is defined), like this:
class Myclass{
static int iCount;
} ;
int Myclass::iCount=1;
int main(){
/*** use Myclass::iCount here ****/
}
Similar topic:
Because C++ syntax doesn't allow this. You need to instantiate your static variable outside of the scope of some function.
Besides you forget a semicolon ; after your class ending bracket.
this is the correct C++. Outside of a function, in a cpp file. the initialisation is done at the beginning/launching of the executable. ( even before calling main() );
//main.h
class Myclass{
static int iCount;
}; // and don't forget this ";" after a class declaration
//main.cpp
int Myclass::iCount=1;
int main(){
}
From C++ standard (§8.5/10):
An initializer for a static member is in the scope of the member’s class.
class Myclass has global scope and you tried to initialize its static member in the narrower scope - of the function main.
The static initialisation occurs before main is called by the run-time initialisation.
Placing it within a function is not allowed because that is where locally scoped objects are declared. It would be confusing and ambiguous to allow that.
