GraphQL MCQ

GraphQL offers a query language for your API and a runtime for executing those queries with your existing data. If you're setting foot into this fascinating world, this MCQ guide will test and strengthen your basic understanding. Let's jump right in!

1. What is GraphQL?

a) A Database

b) A Web Framework

c) A Query Language for your API

d) An HTTP Client

Answer:

c) A Query Language for your API

Explanation:

GraphQL is a query language designed for APIs, not a database or a web framework.

2. Which HTTP method does GraphQL typically use?

a) GET

b) POST

c) DELETE

d) PUT

Answer:

b) POST

Explanation:

GraphQL typically uses POST method to send both queries and mutations.

3. In GraphQL, what is a "mutation"?

a) A request to read data

b) A syntax error in the query

c) A request to change data

d) A type of response

Answer:

c) A request to change data

Explanation:

In GraphQL, "mutations" are used to change or modify data.

4. Which of the following best describes a GraphQL resolver?

a) A function to discover the database

b) A function that defines the schema

c) A function to transform response data

d) A function that fetches the data for a particular field

Answer:

d) A function that fetches the data for a particular field

Explanation:

Resolvers in GraphQL determine how to fetch the data for a particular field.

5. How do you specify the shape of your return data in a GraphQL query?

a) Using SQL-like syntax

b) With curly braces {}

c) Using XML

d) With square brackets []

Answer:

b) With curly braces {}

Explanation:

In GraphQL, curly braces {} are used to specify the shape of the returned data.

6. Which of the following is a core feature of GraphQL?

a) Always retrieves all fields of an entity

b) Enables over-fetching of data

c) Allows clients to specify their data needs

d) Based on fixed server endpoints

Answer:

c) Allows clients to specify their data needs

Explanation:

One of the core features of GraphQL is that it lets clients specify exactly what data they need.

7. Which GraphQL concept describes a set of rules to create consistent, type-safe, and easily evolvable API schemas?

a) Resolvers

b) Schemas

c) Directives

d) Type System

Answer:

d) Type System

Explanation:

The GraphQL Type System defines the set of rules required for creating consistent and type-safe schemas.

8. What does a ! in a GraphQL schema signify?

a) The field is outdated

b) The field is an array

c) The field is nullable

d) The field is non-nullable

Answer:

d) The field is non-nullable

Explanation:

In a GraphQL schema, a ! indicates that the field is non-nullable.

9. Which of the following is NOT true about GraphQL?

a) GraphQL always returns a 200 OK HTTP status code, even if there's an error

b) GraphQL can be used only with React

c) GraphQL operations can be batched into one request

d) GraphQL allows for real-time data with subscriptions

Answer:

b) GraphQL can be used only with React

Explanation:

GraphQL is not tied to any specific frontend framework like React. It can be used with any frontend or backend technology.

10. In GraphQL, which keyword is used to group multiple operations in one request?

a) Group

b) Bundle

c) Batch

d) Aggregate

Answer:

c) Batch

Explanation:

"Batch" is the term commonly used in the GraphQL ecosystem to describe grouping multiple operations into one request.

11. Which type of operation in GraphQL is used to maintain a real-time connection with the server?

a) Query

b) Mutation

c) Subscription

d) Commit

Answer:

c) Subscription

Explanation:

Subscriptions in GraphQL allow for real-time functionality by maintaining a persistent connection with the server.

12. Which tool is often used to experiment with GraphQL queries in a visual interface?

a) GraphiQL

b) GraphQL Playground

c) Both GraphiQL and GraphQL Playground

d) JSON Viewer

Answer:

c) Both GraphiQL and GraphQL Playground

Explanation:

Both GraphiQL and GraphQL Playground are popular tools that provide a visual interface to experiment with GraphQL queries.

13. What role does the @deprecated directive play in GraphQL?

a) It signifies that a field should not be used.

b) It automatically deletes the field after a set time.

c) It ensures that the field is always fetched.

d) It optimizes the response time of a field.

Answer:

a) It signifies that a field should not be used.

Explanation:

In GraphQL, the @deprecated directive is used to indicate that a field is no longer recommended for use and may be removed in the future.

14. What is the primary advantage of using GraphQL fragments?

a) To increase the query speed

b) To split queries into multiple requests

c) To reuse parts of queries

d) To encrypt the query data

Answer:

c) To reuse parts of queries

Explanation:

Fragments in GraphQL allow users to construct sets of fields, and then include them in queries where you need to.

15. How do you pass dynamic values in a GraphQL query?

a) Using static values

b) Using curly braces {}

c) Using arguments

d) Using annotations

Answer:

c) Using arguments

Explanation:

In GraphQL, you pass dynamic values into a query using arguments.

16. What does a GraphQL Schema define?

a) The underlying database structure

b) The transport protocol to be used

c) The types and shapes of responses and requests between the client and server

d) The methods for caching responses

Answer:

c) The types and shapes of responses and requests between the client and server

Explanation:

A GraphQL schema defines the capabilities of the API by specifying the data types and operations available.

17. Which of the following is NOT a part of a GraphQL server's responsibilities?

a) Parsing and validating the GraphQL request

b) Executing the request by invoking the required resolvers

c) Managing the database connections

d) Delivering the response to the client in JSON format

Answer:

c) Managing the database connections

Explanation:

While a GraphQL server does handle the request and invokes resolvers, it doesn't specifically manage database connections. That would typically be handled by other parts of the backend or database drivers.

18. How can you fetch data from multiple sources in a single GraphQL query?

a) Using multiple endpoints

b) By chaining multiple queries

c) By combining fragments

d) Through the use of resolvers fetching from various sources

Answer:

d) Through the use of resolvers fetching from various sources

Explanation:

GraphQL allows for a single query to fetch data from multiple sources. This is accomplished through resolvers, which can fetch data from various sources, such as databases, REST APIs, third-party services, etc.

19. What would be a primary reason to use GraphQL over a traditional REST API?

a) GraphQL queries are faster.

b) REST doesn't allow fetching data.

c) GraphQL allows clients to request only the data they need.

d) GraphQL uses a different transport protocol.

Answer:

c) GraphQL allows clients to request only the data they need.

Explanation:

One of the significant benefits of GraphQL over traditional REST is that it allows clients to specify exactly the data they need, preventing over-fetching or under-fetching of data.

20. Is GraphQL frontend or backend specific?

a) Frontend only

b) Backend only

c) Neither. It acts as an interface between the frontend and backend.

d) Both. It can be integrated into both frontend and backend systems.

Answer:

c) Neither. It acts as an interface between the frontend and backend.

Explanation:

GraphQL is neither frontend nor backend specific. It provides a layer that sits in between, serving as an interface for frontend to fetch and manipulate data from backend systems.