Factory(Simplified version of Factory Method) - Creates objects without exposing the instantiation logic to the client and Refers to the newly created object through a common interface.
Factory Method - Defines an interface for creating objects, but let subclasses to decide which class to instantiate and Refers to the newly created object through a common interface.
Builder - Defines an instance for creating an object but letting subclasses decide which class to instantiate and Allows a finer control over the construction process.
Chain of Responsibiliy - It avoids attaching the sender of a request to its receiver, giving this way other objects the possibility of handling the request too. - The objects become parts of a chain and the request is sent from one object to another across the chain until one of the objects will handle it.
Sourcecode:
Click to zoom Restaurant Example
Command - Encapsulate a request in an object, Allows the parameterization of clients with different requests and Allows saving the requests in a queue.
Interpreter - Given a language, define a representation for its grammar along with an interpreter that uses the representation to interpret sentences in the language / Map a domain to a language, the language to a grammar, and the grammar to a hierarchical object-oriented design
Mediator - Define an object that encapsulates how a set of objects interact. Mediator promotes loose coupling by keeping objects from referring to each other explicitly, and it lets you vary their interaction independently.
Sourcecode:
Click to zoom News Publisher Example
Observer - Define a one-to-many dependency between objects so that when one object changes state, all its dependents are notified and updated automatically.
Strategy - Define a family of algorithms, encapsulate each one, and make them interchangeable. Strategy lets the algorithm vary independently from clients that use it.
Template Method - Define the skeleton of an algorithm in an operation, deferring some steps to subclasses / Template Method lets subclasses redefine certain steps of an algorithm without letting them to change the algorithm's structure.
Visitor - Represents an operation to be performed on the elements of an object structure / Visitor lets you define a new operation without changing the classes of the elements on which it operates.
Null Object - Provide an object as a surrogate for the lack of an object of a given type. / The Null Object Pattern provides intelligent do nothing behavior, hiding the details from its collaborators.
Sourcecode:
Structural Design Patterns:
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Adapter - Convert the interface of a class into another interface clients expect. / Adapter lets classes work together, that could not otherwise because of incompatible interfaces.
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Bridge - Compose objects into tree structures to represent part-whole hierarchies. / Composite lets clients treat individual objects and compositions of objects uniformly.
Composite - Compose objects into tree structures to represent part-whole hierarchies. / Composite lets clients treat individual objects and compositions of objects uniformly.
Memento - capture the internal state of an object without violating encapsulation and thus providing a mean for restoring the object into initial state when needed.