This presentation intends to be an introduction to Design Patterns, and elaborate their importance with a small example. Its intention is to orient the audience to start exploring more on the topic.

1. Design Patterns Abhishek Chatterjee

7. An Orientation Example – Strategy Pattern Duck quack() swim() abstract display() MallardDuck display() RedheadDuck display() Lots of other types of ducks

8. An Orientation Example – Strategy Pattern Duck quack() swim() abstract display() fly() MallardDuck display() RedheadDuck display() Lots of other types of ducks

9. An Orientation Example – Strategy Pattern Duck quack() swim() abstract display() fly() MallardDuck display() RedheadDuck display() Lots of other types of ducks

10. An Orientation Example – Strategy Pattern Duck quack() swim() abstract display() fly() MallardDuck display() RedheadDuck display() Yay!! I can fly too!!! RubberDuck display()

12. Hey Abbey-Shack…. If you want to try Monster.com’s resume services, now is the time.

13. Who is going to rescue me now? <<Interfaces>> !!! Yes!!! That’s it! I make an IFlyable interface and RubberDuck doesn’t get to implement it… MallardDuck <<IFlyable>> display() RedheadDuck <<IFlyable>> display() RubberDuck //You can’t fly! display() They can’t see me happy 

14. I… I… I… I have a Question! SimCorp simulates 50 ducks… are you saying you are going to write 50 fly methods? What if there is a change in flying style and it effects 20 ducks… will all 20 ducks change? I am losing money you know…

16. Strategy Pattern in Action Duck quack() swim() abstract display() MallardDuck IFlyBehavior:FlyWithWings display() RubberDuck IFlyBehavior: DontFly display() IFlyBehavior fly() FlyWithWings FlyWithRocket DontFly

20. Q & A

21. Thank You