Inf3220: Design Patterns

Front 1

Abstract Factory

Back 1

Provide and interface for creating failies of related or dependent objects without specifying their conceret classes.

Front 2

Builder

Back 2

Separate the construction of a complex object form its repressentation so that the same construction process can create dfiferent representations.

Front 3

Factory Method

Back 3

Define an dinstnace for creating and object but let subclasses decide whcih class to instantiate Factory methods lets a class defer instantiation to subclasses

Front 4

Prototype

Back 4

Specify the kinds of objects to create using a prototypical instnace, and create new objects by copying this prototype.

Front 5

Singleton

Back 5

Ensurea class only has one instance, and provdie a global point of access to it

Front 6

Adaptyer

Back 6

Convert tthe interface of a class into another interface clients expect. Adapter lets classes work together tha couldn't otherwise because of incompatible interfaces.

Front 7

Bridge

Back 7

Decople an abstraction from its implementation so that hte two can vary independently

Front 8

Composite

Back 8

Comopse objects into tree sturctures to representat part-whole hierarchies. COmposite lets clients treat individual objects and compositions of obejcst uniformly

Front 9

Decorator

Back 9

Attach additional responsibilties to an object dynamimcally. Decorators proide a flexible alternative to subclassing for extending functionality.

Front 10

Facade

Back 10

Provide a unified interface to a set of interfaces in a subsystem.
Facade defines a higher level interface that maeks the subsystem easire to use.

Front 11

Flyweight

Back 11

Using sharing to support large numbers of fine-grained objects efficiently

Front 12

Proxy

Back 12

Provide a surrogate palcehodler for another object to control access to it.

Front 13

Chain of REsponsibility

Back 13

Avoid couplint he sender of a request to its receiver by givien more than obne object a chance to hande the request. Chain the receiveing objects and pass the request along hte chain until a n object handles it.

Front 14

Command

Back 14

Encapsuate a request as an object, thereby letting you parametize clients with differnet requests, queu e or log requests, and support undoable operations.

Front 15

Interpreter

Back 15

Given a anaugage, define a represenation for its gramar along with an interpreter that uses the representation to interpret stentences in the langauge.

Front 16

Iterator

Back 16

Provide a way to access the elemetns fo an aggregate object sequentially without exposing its underlying represetnation.

Front 17

Meidator

Back 17

Define an object htat encapsulates how a set of objets interfact. Mediator promotes loose coupling by keeping objects from referring ot each other explicitly and it lets you vary their interaction independently.

Front 18

Memento

Back 18

Without violating encapsulation, capture and externalise and object's inernal state sothat the object can be restored to the state later.

Front 19

OBserver

Back 19

Defina one-to-many dependency between objecs to sthat when one object changes state, all its dependensts are notified and updated uatomatically.

Front 20

State

Back 20

ALlow an object ao lter its behaviour when its internal state changes. THe object will aprear to change its clas.

Front 21

Strategy

Back 21

Define a family of algorithms, encapsulate each one and make them interchangeable. Stragetylets the algorithm vary independtly from clients that sue it.

Front 22

Template

Back 22

Defin teh skeleton of an algorithm in an operation, deerring some steps to subclasses. Tempmlate method lets subclasses redefine certain steps of an algorithm without chagnign the algorithms strucutre.

Front 23

VIsitor

Back 23

Representa an operation to be performed on teh elements of an obejct structure. Visitor lets you defina new operation without changing hte lcasses of the elemetns on which it operates.