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 about Structural design patterns.
A - These design patterns are specifically concerned with communication between objects.
Answer : C
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 2 - Which of the following describes the Bridge pattern correctly?
A - This pattern builds a complex object using simple objects and using a step by step approach.
B - This pattern refers to creating duplicate object while keeping performance in mind.
C - This pattern is used when creation of object directly is costly.
Answer : D
Explanation
Bridge pattern is used when we need to decouple an abstraction from its implementation so that the two can vary independently.
Q 3 - Which of the following pattern is used when creation of object directly is costly?
Answer : A
Explanation
Prototype pattern is used when creation of object directly is costly.
Q 4 - Which of the following describes the Command 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 : D
Explanation
Command pattern is a data driven design pattern and falls under behavioral pattern category. A request is wrapped under an object as command and passed to invoker object. Invoker object looks for the appropriate object which can handle this command and passes the command to the corresponding object which executes the command.
Q 5 - Which of the following pattern a request is wrapped under an object as command and passed to invoker object?
Answer : C
Explanation
A request is wrapped under an object as command and passed to invoker object. Invoker object looks for the appropriate object which can handle this command and passes the command to the corresponding object which executes the command.
Q 6 - Which of the following describes the Strategy 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 : C
Explanation
In Strategy pattern, a class behavior or its algorithm can be changed at run time.
Q 7 - Which of the following describes the Intercepting pattern correctly?
D - This pattern is used when we want to locate various services using JNDI lookup.
Answer : C
Explanation
Intercepting pattern, is used when we want to do some pre-processing / post-processing with request or response of the application.
Q 8 - In which of the following pattern an interface is responsible for creating a factory of related objects without explicitly specifying their classes?
Answer : B
Explanation
In Abstract Factory Pattern an interface is responsible for creating a factory of related objects without explicitly specifying their classes.
Q 9 - Which type of design patterns concern class and object composition?
A - Creational Design Patterns
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 DAO pattern?
A - Data Access Object Interface, Data Access Object concrete class, Model Object or Value Object
B - Data Access Object Interface, Model Object or Value Object
C - Data Access Object Interface, Data Access Object concrete class
D - Data Access Object concrete class, Model Object or Value Object
Answer : A
Explanation
Data Access Object Interface, Data Access Object concrete class, Model Object or Value Object are the entities of DAO Pattern.
