Behavioral Design Patterns

What is the primary purpose of the Observer design pattern?

• To define a family of algorithms and make them interchangeable.

• To provide an interface for creating families of related or dependent objects.

• 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 ensure a class has only one instance and provide a global point to access it.

Which behavioral design pattern defines a way to encapsulate a request as an object, thereby allowing for parameterization of clients with different requests, queuing of requests, and logging of the parameters?

• Observer Pattern

• Strategy Pattern

• Command Pattern

• State Pattern

What problem does the Chain of Responsibility pattern address?

• It provides an interface for creating families of related or dependent objects without specifying their concrete classes.

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

• It avoids coupling the sender of a request to its receiver by giving more than one object a chance to handle the request.

• It defines a family of algorithms, encapsulates each algorithm, and makes the algorithms interchangeable.

Which behavioral design pattern allows an object to alter its behavior when its internal state changes, and the object will appear to change its class?

• Observer Pattern

• State Pattern

• Command Pattern

• Visitor Pattern

What does the Memento pattern achieve in terms of behavior?

• It defines a family of algorithms, encapsulates each algorithm, and makes the algorithms interchangeable.

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

• It captures and externalizes an object's internal state so that it can be restored to this state later.

• It allows an object to alter its behavior when its internal state changes.

What does the Interpreter pattern accomplish in terms of behavior?

• It defines a family of algorithms, encapsulates each algorithm, and makes the algorithms interchangeable.

• It allows an object to alter its behavior when its internal state changes.

• It captures and externalizes an object's internal state so that it can be restored to this state later.

• It defines a grammar for interpreting the sentences of a language and provides an interpreter for the language.

In the Template Method pattern, what is the role of the template method?

• It defines the interface for creating objects but leaves the choice of their types to the subclasses, creating an instance of several derived classes.

• It defines the skeleton of an algorithm in the superclass but lets subclasses override specific steps of the algorithm without changing its structure.

• It allows an object to alter its behavior when its internal state changes.

• It provides an interface for creating families of related or dependent objects without specifying their concrete classes.

What does the Strategy pattern achieve in terms of behavior?

• It defines a family of algorithms, encapsulates each algorithm, and makes the algorithms interchangeable.

• It provides an interface for creating families of related or dependent objects without specifying their concrete classes.

• It allows an object to alter its behavior when its internal state changes.

• It captures and externalizes an object's internal state so that it can be restored to this state later.

What is the purpose of the Iterator pattern in behavioral design?

• It defines a family of algorithms, encapsulates each algorithm, and makes the algorithms interchangeable.

• It provides a way to access the elements of an aggregate object sequentially without exposing its underlying representation.

• It captures and externalizes an object's internal state so that it can be restored to this state later.

• It allows an object to alter its behavior when its internal state changes.

In the Mediator pattern, what is the primary responsibility of the Mediator?

• It defines a family of algorithms, encapsulates each algorithm, and makes the algorithms interchangeable.

• It provides an interface for creating families of related or dependent objects without specifying their concrete classes.

• It captures and externalizes an object's internal state so that it can be restored to this state later.

• It defines an object that centralizes communication between a set of objects, promoting loose coupling between them.