Factory Method

Strategy

Observer

Singleton

To define a one-to-many dependency between objects so that when one object changes state, all its dependents are notified and updated automatically.

To create a single instance of a class and provide a global point of access to that instance.

To provide a way to add or remove objects from a collection dynamically.

To define an interface for creating objects, but let subclasses decide which class to instantiate.

Factory Method

Strategy

Observer

Singleton

To define a family of algorithms, encapsulate each one, and make them interchangeable.

To create a single instance of a class and provide a global point of access to that instance.

To provide a way to add or remove objects from a collection dynamically.

To define an interface for creating objects, but let subclasses decide which class to instantiate.

Factory Method

Strategy

Observer

Composite

To convert the interface of a class into another interface clients expect.

To define a family of algorithms, encapsulate each one, and make them interchangeable.

To provide a way to add or remove objects from a collection dynamically.

To define an interface for creating objects, but let subclasses decide which class to instantiate.

Factory Method

Abstract Factory

Builder

Prototype

To define a family of related classes and provide a way to create objects without specifying their exact class.

To convert the interface of a class into another interface clients expect.

To provide a way to add or remove objects from a collection dynamically.

To define an interface for creating objects, but let subclasses decide which class to instantiate.

Factory Method

Abstract Factory

Builder

Prototype

To attach additional responsibilities to an object dynamically.

To convert the interface of a class into another interface clients expect.

To provide a way to add or remove objects from a collection dynamically.

To define an interface for creating objects, but let subclasses decide which class to instantiate.

Command

Memento

Observer

Singleton

To provide a way to undo or redo actions.

To convert the interface of a class into another interface clients expect.

To provide a way to add or remove objects from a collection dynamically.

To define an interface for creating objects, but let subclasses decide which class to instantiate.

Iterator

Composite

Observer

Singleton

To provide a way to access the elements of an aggregate object sequentially without exposing its underlying representation.

To convert the interface of a class into another interface clients expect.

To provide a way to add or remove objects from a collection dynamically.

To define an interface for creating objects, but let subclasses decide which class to instantiate.

Factory Method

Abstract Factory

Builder

Prototype