Free Basic Design Pattern Question and Answers

Question 1

Give a subsystem's collection of interfaces a unified interface. It defines a higher level interface that facilitates use of the subsystem.

Accepted Answer

Facade

Answer

Mediator

Answer

Adapter

Answer

Strategy

Question 2

Define an operation that contains the basic structure of an algorithm while leaving some phases to subclasses. It enables subclasses to modify specific algorithmic stages without altering the algorithm's structure.

Accepted Answer

Template method

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Interpretor

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Prototype

Answer

Chain of responsibility

Question 3

Enables sequential access to the components of an aggregate object without disclosing its underlying representation.

Accepted Answer

Iterator

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Composite

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Command

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Visitor

Question 4

Which statement regarding the Singleton design pattern is true.

Accepted Answer

All of the above

Answer

A singleton class provides a method of accessing its single object directly without the requirement to initialize the class's object.

Answer

Creational patterns include this kind of design pattern.

Answer

In this pattern, a single class is in charge of creating an object while ensuring that only one object is produced.

Question 5

Dynamically assign extra responsibilities to an object. It offers a versatile substitute for subclassing when it comes to extending functionality.

Accepted Answer

Decorator

Answer

Chain of responsibility

Answer

Composite

Answer

Adapter

Question 6

Encapsulate a request as an object to provide undoable operations, parametrize clients with various requests, and queue or log requests.

Accepted Answer

Command

Answer

Decorator

Answer

Adapter

Answer

Composite

Question 7

Establishes an interface for object creation but leaves it up to the subclasses to choose the class to instantiate. It let subclasses' instantiations to vary.

Accepted Answer

Factory Method

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Abstract Factory

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Prototype

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Builder