Creational pattern

• Creational design patterns are design patterns that deal with object creation mechanisms, trying to create objects in a manner suitable to the situation. 
• The basic form of object creation could result in design problems or in added complexity to the design. Creational design patterns solve this problem by somehow controlling this object creation.
• Creational design patterns are composed of two dominant ideas.
• Encapsulating knowledge about which concrete classes the system uses.
• Hiding how instances of these concrete classes are created and combined.
• Creational design patterns are further categorized as
• Object-creational patterns
• Object-creational patterns deal with Object creation.
• Object creation to another object
• Class-creational patterns
• Class-creational patterns deal with Class-instantiation.
• Object creation to subclasses.
• Five well-known design patterns that are parts of creational patterns are the
• Builder pattern
• Separate the construction of a complex object from its representation so that the same construction process can create different representations
• Factory method pattern
• Centralize creation of an object of a specific type choosing one of several implementations
• Abstract factory pattern
• A class requests the objects it requires from a factory object instead of creating the objects directly
• Singleton pattern
• Restrict instantiation of a class to one object
• Prototype pattern
• Used when the type of objects to create is determined by a prototypical instance, which is cloned to produce new objects
• Dependency Injection pattern
• A accepts the objects it requires from an injector instead of creating the objects directly