Design Pattern Learning experience 4

1. Combination mode

Define a parent class, which includes the method interface for all subclasses, then for any one subclass the external boundary is closed, the outside world only calls the interface of the parent class, and does not know whether the child class has an implementation.

2. Iterator mode

This is common in C + +, which is often used in standard template classes, and its function is to traverse the members of a class without the outside knowing the members of the object.

3. Single-Case mode

This pattern is for only one instance, the workaround is to set the constructor to private function, and the instantiation of the class uses a common static function interface.

Design Pattern Learning experience 4