Adapter pattern in LLD - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Purpose of the Adapter Pattern

Which of the following best describes the main purpose of the Adapter pattern in system design?

A To allow incompatible interfaces to work together by converting one interface into another expected by clients.

B To provide a way to access elements of a collection sequentially.

C To enforce strict type checking at compile time.

D To create multiple instances of a class to improve performance.

💡 Hint

Think about how two parts of a system with different interfaces can communicate.

The Adapter pattern acts as a bridge between two incompatible interfaces, allowing them to work together without changing their existing code.

❓ Architecture

intermediate

Identifying Adapter Pattern Components

In the Adapter pattern, which component is responsible for implementing the target interface and holding a reference to the adaptee?

A Adaptee

B Adapter

C Client

D Target

💡 Hint

This component acts as a bridge between the client and adaptee.

The Adapter implements the target interface and holds a reference to the adaptee, translating calls from the client to the adaptee.

❓ scaling

advanced

Scaling Adapter Pattern in Large Systems

When scaling a system that uses multiple adapters for different incompatible interfaces, which approach best maintains system scalability and manageability?

A Use a registry or factory to manage and provide specific adapters dynamically based on client requests.

B Create a single monolithic adapter that handles all interface conversions.

C Hardcode adapter selection logic inside the client code for each interface type.

D Duplicate adapter code for each client to reduce dependencies.

💡 Hint

Think about how to avoid tight coupling and improve flexibility when many adapters exist.

Using a registry or factory pattern to manage adapters allows dynamic selection and easier maintenance, improving scalability.

❓ tradeoff

advanced

Tradeoffs of Using Adapter Pattern

What is a common tradeoff when applying the Adapter pattern in system design?

A It always improves performance by reducing method calls.

B It reduces code readability by merging unrelated functionalities into one class.

C It eliminates the need for interfaces, simplifying the design.

D It increases system complexity by adding extra layers but improves flexibility and reusability.

💡 Hint

Consider what happens when you add an extra component between client and adaptee.

Adapters add an extra layer which can increase complexity but allow incompatible interfaces to work together, enhancing flexibility.

❓ component

expert

Request Flow in Adapter Pattern

Consider a client calling a method on a target interface implemented by an adapter, which internally calls the adaptee's method. What is the correct sequence of method calls in this flow?

A 2,1,3,4

B 1,3,2,4

C 1,2,3,4

D 1,2,4,3

💡 Hint

Follow the call from client to adaptee step-by-step.

The client calls the target interface method, the adapter translates and forwards the call to the adaptee, which executes and returns the result.