Introduction - If you have any usage issues, please Google them yourself
Class is a major tool for modular program, which encapsulates a data structure and the data structure of a set of operations is the destruction of information Friends of the hidden member of a mechanism, the main purpose is to consider the efficiency of program static data members The role is to share data between multiple modules. Provide a static member function static data members of the operation of the package and not dependent on co-operation of object data