Static variables can not be initialized in a class as class is building block of the object and you can not allocate memory for class but of class object. Static variable needs to be initialized outside the class.
Static class member initialized to zero when the first object of the class is created no further initialisation is required. for example class text { }; void main() { text t1.t2; // (comment)here the first object is created so static class member initialised to zero. }
Static members of a class are usually initialized outside the definition of class block. Look at the following:
class static_member_class { public: static int i; }
int static_member_class::i 0;
In the above example static_member_class has a static member data 'i' of integer type. However the static member data is initialized out of the class definition withe class scope.
Here many people argue here that while initializing the static member specifying datatype (here 'int') is optional. In the above example we could have initialized the variable like
static_member_class::i 0;
and this is perfectly fine for any standard c++ compiler. But specidying the datatype is required when we are declaring a static member data of any user defined type. In such situations we have to explicitly specify the user defined data type before initializing the static data.
static members can not be initialised within the class. Because what appears inside the class is just a declaration (note that declaring the static member within the class is mandatory along with it you also have to define it separately outside the class). Static member has to be defined and initialised outside the class(if you wont initialise its default value will be zero).
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