Factory method pattern)

Defines an interface used to create objects, so that the subclass determines which class to instantiate. The factory method delays the instantiation of a class to the subclass.
Static Graph

Intention
Defines an interface used to create objects, so that the subclass determines which class to instantiate. Factory method to instantiate a class
Delay to its subclass.
Applicability
When a class does not know the class of the object it must create.
When a class wants its subclass to specify the object it creates.
When a class delegates the responsibility of creating an object to one of multiple help sub-classes, and you want to localize the information of which help sub-classes are proxies.
Summary
Factory method pattern does not use a special class to determine which subclass to instantiate. On the contrary, superclasses delay this decision to every subclass. This mode does not actually have a decision point, and does not directly select a decision for subclass instantiation. A program written in this mode defines an abstract class to create an object, but the subclass decides to create an object.
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