Pattern Design Behavioral Design Patterns

Question 1

Which behavioral pattern defines a one-to-many dependency so that when one object changes state, all dependents are notified automatically?

Accepted Answer

Observer

Answer

Mediator

Answer

Command

Answer

Strategy

Question 2

The Strategy pattern allows:

Accepted Answer

Swapping algorithms at runtime without changing the client

Answer

Defining a skeleton algorithm with deferred steps

Answer

Encapsulating requests as objects

Answer

Traversing a collection without exposing its structure

Question 3

The Command pattern encapsulates a request as an object primarily to support:

Accepted Answer

Undo/redo, queuing, and logging of operations

Answer

State-based transitions

Answer

Recursive tree traversal

Answer

Simplified access to a subsystem

Question 4

Template Method pattern enforces an algorithm's structure by:

Accepted Answer

Defining the skeleton in a base class with some steps deferred to subclasses

Answer

Delegating all steps to a strategy object

Answer

Using chain of handlers for each step

Answer

Storing state transitions in a state machine

Question 5

Which behavioral pattern is used to traverse elements of a collection without exposing the underlying representation?

Accepted Answer

Iterator

Answer

Visitor

Answer

Interpreter

Answer

Memento

Question 6

The Chain of Responsibility pattern passes a request along a chain until:

Accepted Answer

A handler processes it or the chain ends

Answer

All handlers process it in sequence

Answer

Only the first handler processes it

Answer

The request is stored as a Command object