Initialization of static members, static const members, and const members in C ++

(1) Static members should be initialized outside the class: such members belong to the entire class, but they are very large, so they can be initialized outside the class, or they can be initialized using static functions.

Class A <br/>{< br/> PRIVATE: <br/> static int A; <br/>}; <br/> int A: a = 0; 

 

(2) The const static member can be initialized within the class: such a member is a constant of the entire class.

Class B <br/>{< br/> PRIVATE: <br/> const static int B = 3; <br/> }; 

(3) const members should be initialized in the constructor initialization table: such members are contained in each object, but only constants. Therefore, they must be initialized each time an object is constructed.

Class C <br/>{< br/> Public: <br/> const int size; <br/> C (INT size) <br/>{< br/> // codes <br/>}< br/>}; <br/> C: C (INT size), size (size) <br/>{< br/> // codes <br/>}