Friday, June 18, 2010

Design Pattern Interview Questions

  1. Explain the Flyweight, Builder, Mediator and Memento patterns.
  2. Describe the decorator pattern and how it is used within the package.

    Answer: Decorators are used to provide additional functionality to an object of some kind. The key to a decorator is that a decorator "wraps" the object decorated and looks to a client exactly the same as the object wrapped. This means that the decorator implements the same interface as the object it decorates. For example, a BufferedReader is just a decorator for a Reader.

  3. Observer Pattern:
    • Draw the class diagram for the Observer Pattern.
    • What instance variables would you have in the Observable class?
    • What would happen if an Observer removes himself from the observers list when he is notified?
    • What is thread-safety and how can you make the Observer Pattern thread-safe?
  4. Name your favourite design pattern.
  5. Explain the Model-View-Controller (MVC) compound design pattern. What patterns is it composed of?
More Interview Posts


  1. Good work

  2. Hi

    Tks very much for post:

    I like it and hope that you continue posting.

    Let me show other source that may be good for community.

    Source: Mock interview questions

    Best rgs