200-901 Question 16
Select 2A development team is building a web application that requires frequent updates to the user interface whenever the data changes, and they also want to maintain a clear separation of concerns between the data, business logic, and presentation layers. Which design patterns would best address these requirements?
- A
Model-View-Controller (MVC)
- B
Observer
- C
Singleton
- D
Factory Method
- E
Decorator
Show answer and explanation
Correct answers: A, B
Explanation
The MVC pattern is ideal for maintaining a clear separation between data, business logic, and presentation layers, which enhances maintainability and scalability. The Observer pattern complements this by enabling dynamic updates to the user interface whenever the underlying data changes. Together, these patterns address the requirements of the scenario effectively.
- A. Correct.
The Model-View-Controller (MVC) pattern is highly effective for applications requiring a clear separation of concerns. The model manages the data, the view handles the user interface, and the controller coordinates between them, making it ideal for scenarios with frequent updates to the UI.
- B. Correct.
The Observer pattern allows objects (observers) to subscribe to changes in another object (subject). This is particularly useful when the user interface needs to be updated dynamically whenever data changes, as in this scenario.
- C. Incorrect.
The Singleton pattern ensures a class has only one instance and provides global access to it. While useful in some cases, it is not relevant to separating concerns or updating UIs dynamically in this scenario.
- D. Incorrect.
The Factory Method pattern focuses on creating objects without specifying their concrete classes. While useful for object creation, it does not address the specific requirements of dynamic UI updates or separation of concerns.
- E. Incorrect.
The Decorator pattern is used to extend the functionality of objects dynamically. It does not focus on UI updates or separation of concerns and is therefore not applicable to this scenario.