What are Design Patterns?
Design patterns are recurring solution to recurring problems in software architecture.
Which Design Patterns are you familiar with?
Left up to you pick any three patterns which you are known and have used in your project and talk about it. By this interviewer will come know that you are not new to Design Patterns.
Can you explain Singleton Pattern?
Singleton pattern helps us to create a single instance of an object which can be shared across project. Main use of singleton pattern is for global data sharing and caching.
What is MVC, MVP and MVVM pattern?
All the above design patterns come in presentation pattern category and help to remove any kind of cluttered code in UI like manipulation of user interfaces and maintaining state. Thus it keeps your UI code cleaner and better to maintain.
MVC pattern divides the architecture in to 3 part model, view and controller. The first request comes to the controller and the controller then decides which view to be displayed and ties up the model with the view accordingly.
MVP (Model view presenter) has the same goals as MVC i.e. separating the UI from the model. It does the same by using a presenter class. The UI talks via an interface to the presenter class and the presenter class talks with the model.
MVVM is an architectural pattern with the focus of removing UI cluttered code. It does the same by using an extra class called as view model. MVVM is mostly suitable for SilverLight and WPF projects because of the rich bindings provided by the technologies.
See following video on Factory Design Pattern: -
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