Structural patterns (Adapter, Decorator, Facade) in Software Engineering - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the main purpose of the Adapter pattern?

The Adapter pattern helps two incompatible interfaces work together by converting the interface of one class into another that clients expect.

beginner

How does the Decorator pattern add functionality to an object?

The Decorator pattern wraps an object with another object that adds new behavior or responsibilities without changing the original object's code.

beginner

What problem does the Facade pattern solve?

The Facade pattern provides a simple interface to a complex system, making it easier to use by hiding the system's complexity behind a single unified interface.

intermediate

Which structural pattern would you use to make two incompatible classes work together without changing their code?

You would use the Adapter pattern because it acts as a bridge between incompatible interfaces.

beginner

Can the Decorator pattern change the original object's code?

No, the Decorator pattern adds new behavior by wrapping the original object, leaving its code unchanged.

Which pattern provides a simplified interface to a complex system?

A Adapter

B Facade

C Decorator

D Observer

The Facade pattern offers a simple interface to hide the complexity of a system.

What does the Adapter pattern do?

A Converts one interface to another

B Adds new behavior by wrapping objects

C Simplifies complex systems

D Manages object creation

Adapter converts one interface into another to make incompatible interfaces work together.

Which pattern allows adding responsibilities to objects dynamically?

A Facade

B Adapter

C Decorator

D Singleton

Decorator wraps objects to add new responsibilities without changing their code.

If you want to hide complex subsystem details from clients, which pattern should you use?

A Adapter

B Factory

C Decorator

D Facade

Facade hides complexity by providing a simple interface.

Which pattern is best for making two incompatible interfaces work together?

A Adapter

B Facade

C Decorator

D Proxy

Adapter acts as a bridge between incompatible interfaces.

Explain the differences between Adapter, Decorator, and Facade patterns with examples.

Think about how each pattern changes or hides complexity.

Describe a real-life scenario where you would use the Facade pattern.

Consider something like a home entertainment system or a car dashboard.