Creational Design Patterns
- Design Patterns - Factory Pattern
- Abstract Factory Pattern
- Design Patterns - Singleton Pattern
- Design Patterns - Builder Pattern
- Design Patterns - Prototype Pattern
Structural Design Patterns
- Design Patterns - Adapter Pattern
- Design Patterns - Bridge Pattern
- Design Patterns - Filter Pattern
- Design Patterns - Composite Pattern
- Design Patterns - Decorator Pattern
- Design Patterns - Facade Pattern
- Design Patterns - Flyweight Pattern
- Design Patterns - Proxy Pattern
- Chain of Responsibility Pattern
Behavioral Design Patterns
- Design Patterns - Command Pattern
- Design Patterns - Interpreter Pattern
- Design Patterns - Iterator Pattern
- Design Patterns - Mediator Pattern
- Design Patterns - Memento Pattern
- Design Patterns - Observer Pattern
- Design Patterns - State Pattern
- Design Patterns - Strategy Pattern
- Design Patterns - Template Pattern
- Design Patterns - Visitor Pattern
J2EE Design Patterns
- Design Patterns - Null Object Pattern
- Design Patterns - MVC Pattern
- Business Delegate Pattern
- Composite Entity Pattern
- Data Access Object Pattern
- Front Controller Pattern
- Intercepting Filter Pattern
- Service Locator Pattern
- Transfer Object Pattern
Design Patterns Useful Resources
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 Singleton design pattern.
A - This type of design pattern comes under creational pattern.
Answer : D
Explanation
Singleton pattern is one of the simplest design patterns in Java. This type of design pattern comes under creational pattern as this pattern provides one of the best ways to create an object.This pattern involves a single class which is responsible to create an object while making sure that only single object gets created. This class provides a way to access its only object which can be accessed directly without need to instantiate the object of the class.
Answer : A
Explanation
true. Wrapper classes like Integer, Boolean uses Decorator pattern.
Q 3 - Which of the following pattern builds a complex object using simple objects and using a step by step approach?
Answer : A
Explanation
Builder Pattern builds a complex object using simple objects and using a step by step approach. This builder is independent of other objects.
Q 4 - Which of the following describes the Chain of Responsibility 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 : B
Explanation
As the name suggests, the chain of responsibility pattern creates a chain of receiver objects for a request.
Q 5 - Which of the following describes the Mediator pattern correctly?
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.
Answer : B
Explanation
This pattern is used to reduce communication complexity between multiple objects or classes.
Q 6 - Which of the following describes the Template 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 : D
Explanation
In Template pattern, an abstract class exposes defined way(s)/template(s) to execute its methods.
Q 7 - Which of the following describes the DAO pattern correctly?
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 creates object without exposing the creation logic to the client and refer to newly created object using a common interface?
Answer : A
Explanation
Factory Pattern creates object without exposing the creation logic to the client and refer to newly created object using a common interface.
Q 9 - Which type of design patterns are specifically concerned with the presentation tier?
A - Creational Design Patterns
Answer : D
Explanation
J2EE Design Patterns are specifically concerned with the presentation tier.
Q 10 - In MVC pattern, Model represents an object or JAVA POJO carrying data. It can also have logic to update controller if its data changes.
Answer : A
Explanation
True. In MVC pattern, Model represents an object or JAVA POJO carrying data. It can also have logic to update controller if its data changes.