Design Patterns Online Quiz

Following quiz provides Multiple Choice Questions (MCQs) related to Design Patterns Framework. You will have to read all the given answers and click over the correct answer. If you are not sure about the answer then you can check the answer using Show Answer button. You can use Next Quiz button to check new set of questions in the quiz.

Q 1 - Which of the following is correct list of classifications of design patterns.

A - Creational, Structural and Behavioral patterns.

B - Executional, Structural and Behavioral patterns.

C - Creational, Executional and Behavioral patterns.

D - None of the above.

Answer : A

Explanation

Design patterns can be classified in three categories: Creational, Structural and Behavioral patterns.

Q 2 - Integer.valueOf is an example of Factory pattern.

A - false

B - true

Answer : B

Explanation

true. Integer.valueOf() returns a Integer instance representing the specified int value.

Q 3 - Which of the following describes the Flyweight pattern correctly?

A - This pattern allows a user to add new functionality to an existing object without altering its structure.

B - This pattern is used where we need to treat a group of objects in similar way as a single object.

C - This pattern is primarily used to reduce the number of objects created and to decrease memory footprint and increase performance.

D - This pattern hides the complexities of the system and provides an interface to the client using which the client can access the system.

Answer : C

Explaination

This pattern is primarily used to reduce the number of objects created and to decrease memory footprint and increase performance.

Q 4 - Which of the following describes the Interpreter pattern correctly?

A - In this pattern a class represents functionality of another class.

B - This pattern creates a chain of receiver objects for a request.

C - This pattern provides a way to evaluate language grammar or expression.

D - In this pattern a request is wrapped under an object as command and passed to invoker object.

Answer : C

Explanation

Interpreter pattern provides a way to evaluate language grammar or expression. This type of pattern comes under behavioral pattern. This pattern involves implementing an expression interface which tells to interpret a particular context.

Q 5 - Which of the following describes the Iterator pattern correctly?

A - This pattern is used to get a way to access the elements of a collection object in sequential manner without any need to know its underlying representation.

B - This pattern is used to reduce communication complexity between multiple objects or classes.

C - This pattern is used to restore state of an object to a previous state.

D - This pattern is used when there is one-to-many relationship between objects such as if one object is modified, its depenedent objects are to be notified automatically.

Answer : A

Explanation

This pattern is used to get a way to access the elements of a collection object in sequential manner without any need to know its underlying representation.

Q 6 - Which of the following describes the Null Object pattern correctly?

A - In this pattern, a class behavior changes based on its state.

B - In this pattern, a null object replaces check of NULL object instance.

C - In this pattern, a class behavior or its algorithm can be changed at run time.

D - In this pattern, an abstract class exposes defined way(s)/template(s) to execute its methods.

Answer : B

Explanation

In Null Object pattern, a null object replaces check of NULL object instance.

Q 7 - Which of the following describes the DAO pattern correctly?

A - This pattern is used to separate low level data accessing API or operations from high level business services.

B - This pattern is used to provide a centralized request handling mechanism so that all requests will be handled by a single handler.

C - This pattern is used when we want to do some pre-processing / post-processing with request or response of the application.

D - This pattern is used when we want to locate various services using JNDI lookup.

Answer : A

Explanation

DAO pattern, is used to separate low level data accessing API or operations from high level business services.

Q 8 - Which of the following pattern is used to provide a centralized request handling mechanism so that all requests will be handled by a single handler?

A - DAO Pattern

B - Front Controller Pattern

C - Intercepting Pattern

D - Service Locator Pattern

Answer : B

Explanation

Front Controller Pattern is used to provide a centralized request handling mechanism so that all requests will be handled by a single handler.

Q 9 - Which of the following describes the Structural pattern correctly?

A - This type of patterns provide a way to create objects while hiding the creation logic, rather than instantiating objects directly using new opreator

B - This type of patterns concern class and object composition. Concept of inheritance is used to compose interfaces and define ways to compose objects to obtain new functionalities.

C - This type of pattern are specifically concerned with communication between objects.

D - This type of pattern are specifically concerned with the presentation tier.

Answer : B

Explanation

Structural Design Patterns concern class and object composition. Concept of inheritance is used to compose interfaces and define ways to compose objects to obtain new functionalities.

Q 10 - Which of the following is the correct list of entities of MVC pattern?

A - Model, View, Controller

B - Model, Viewer, Control

C - Middle, Viewer, Controller

D - Model, View, Control

Answer : A

Explanation

Model, View, Controller are the entities of MVC Pattern.

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