factory method

define interface for creating an object, but let subclass decide which class to instantiate

also know as

virtual constructor

motivation

• encapsulates knowledge of which subclass to instantiate

applicability

• when a class can not anticpate the class of the objects it creates
• to delegate responsibility of object creation

structure

participants

• Product, ConcreteProduct, Creator, ConcreteCreator

consequences

• provide hooks for subclasses
• connects parallel class hierarchies

related

• Factory, Prototype