Behavioural Design Patterns

Behavioural patterns define manners of communication between classes and objects.

Chain of responsibility pattern

The chain of responsibility pattern is used to process varied requests, each of which may be dealt with by a different handler.

Command pattern

The command pattern is used to express a request, including the call to be made and all of its required parameters, in a command object. The command may then be executed immediately or held for later use.

Interpreter pattern

The interpreter pattern is used to define the grammar for instructions that form part of a language or notation, whilst allowing the grammar to be easily extended.

Iterator pattern

The iterator pattern is used to provide a standard interface for traversing a collection of items in an aggregate object without the need to understand its underlying structure.

Mediator pattern

The mediator pattern is used to reduce coupling between classes that communicate with each other. Instead of classes communicating directly, and thus requiring knowledge of their implementation, the classes send messages via a mediator object.

Memento pattern

The memento pattern is used to capture the current state of an object and store it in such a manner that it can be restored at a later time without breaking the rules of encapsulation.

Observer pattern

The observer pattern is used to allow an object to publish changes to its state. Other objects subscribe to be immediately notified of any changes.

State pattern

The state pattern is used to alter the behaviour of an object as its internal state changes. The pattern allows the class for an object to apparently change at run-time.

Strategy pattern

The strategy pattern is used to create an interchangeable family of algorithms from which the required process is chosen at run-time.

Template method pattern

The template method pattern is used to define the basic steps of an algorithm and allow the implementation of the individual steps to be changed.

Visitor pattern

The visitor pattern is used to separate a relatively complex set of structured data classes from the functionality that may be performed upon the data that they hold.

Reference

• Design Patterns Overview 
• Creational Design Patterns Overview 
• Structural Design Patterns Overview 

Structural Design Patterns

Structural patterns provide a manner to define relationships between classes or objects.

Adapter pattern

The adapter pattern is used to provide a link between two otherwise incompatible types by wrapping the "adaptee" with a class that supports the interface required by the client.

Bridge pattern

The bridge pattern is used to separate the abstract elements of a class from the implementation details, providing the means to replace the implementation details without modifying the abstraction.

Composite pattern

The composite pattern is used to create hierarchical, recursive tree structures of related objects where any element of the structure may be accessed and utilized in a standard manner.

Decorator pattern

The decorator pattern is used to extend or alter the functionality of objects at run-time by wrapping them in an object of a decorator class. This provides a flexible alternative to using inheritance to modify behaviour.

Facade pattern

The facade pattern is used to define a simplified interface to a more complex subsystem.

Flyweight pattern

The flyweight pattern is used to reduce the memory and resource usage for complex models containing many hundreds, thousands or hundreds of thousands of similar objects.

Proxy pattern

The proxy pattern is used to provide a surrogate or placeholder object, which references an underlying object. The proxy provides the same public interface as the underlying subject class, adding a level of indirection by accepting requests from a client object and passing these to the real subject object as necessary.

Reference 

• Design Patterns Overview 
• Creational Design Patterns Overview 
• Behavioural Design Patterns Overview

Creational Design Patterns

Provide ways to instantiate single objects or groups of related objects.

Abstract factory pattern

The abstract factory pattern is used to provide a client with a set of related or dependent objects. The "family" of objects created by the factory are determined at runtime.

Builder pattern

The builder pattern is used to create complex objects with constituent parts that must be created in the same order or using a specific algorithm. An external class controls the construction algorithm.

Factory pattern

The factory pattern is used to replace class constructors, abstracting the process of object generation so that the type of the object instantiated can be determined at runtime.

Prototype pattern

The prototype pattern is used to instantiate a new object by copying all of the properties of an existing object, creating an independent clone. This practice is particularly useful when the construction of a new object is inefficient.

Singleton pattern

The singleton pattern ensures that only one object of a particular class is ever created. All further references to objects of the singleton class refer to the same underlying instance.

Reference 

• Design Patterns Overview 
• Structural Design Patterns Overview 
• Behavioural Design Patterns Overview

Design Patterns Overview

Reusable solution of common problem in software design. 

Types of design patterns

• Creational patterns: Provide ways to instantiate single objects or groups of related objects.
• Structural patterns: Provide a manner to define relationships between classes or objects. 
• Behavioural patterns: Define manners of communication between classes and objects. 

Creational patterns 

• abstract factory pattern
• builder pattern
• factory pattern
• prototype pattern
• singleton pattern

Structural patterns 

• adapter pattern
• bridge pattern
• composite pattern
• decorator pattern
• facade pattern
• flyweight pattern
• proxy pattern

Behavioural patterns

• chain of responsibility pattern
• command pattern
• interpreter pattern
• iterator pattern
• mediator pattern
• memento pattern
• observer pattern
• state pattern
• strategy pattern
• template method pattern
• visitor pattern 

Reference

• Creational Design Patterns Overview 
• Structural Design Patterns Overview 
• Behavioural Design Patterns Overview

Creational Design Patterns Overview -- PDF

https://lnkd.in/gFD5rBna

Structural Design Patterns Overview -- PDF

https://lnkd.in/g4FBAgzh

Behavioral Design Patterns Overview -- PDF

https://lnkd.in/gkni_zK4