GraphQL vs REST comparison - Practice Questions

Challenge - 5 Problems

🧠 Conceptual

intermediate

Key difference in data fetching between GraphQL and REST

Which statement best describes how GraphQL differs from REST in fetching data?

A Both GraphQL and REST require multiple endpoints to fetch different data types.

B REST allows clients to request exactly the data they need in a single query, while GraphQL requires multiple endpoints.

C GraphQL allows clients to request exactly the data they need in a single query, while REST often requires multiple endpoints.

D GraphQL does not support querying data, only mutations, unlike REST.

💡 Hint

Think about how many requests are needed to get related data in each approach.

GraphQL lets clients specify exactly what data they want in one request, reducing over-fetching and under-fetching. REST typically uses multiple endpoints, which may require several requests.

🧠 Conceptual

intermediate

Handling versioning in GraphQL vs REST

How is API versioning typically handled differently in GraphQL compared to REST?

A REST uses explicit version numbers in the URL, while GraphQL encourages evolving the schema without versioning.

B GraphQL uses explicit version numbers in the URL, while REST evolves the schema without versions.

C Both GraphQL and REST require version numbers in the URL for every change.

D Neither GraphQL nor REST support versioning.

💡 Hint

Consider how clients adapt to changes in each API style.

REST APIs often use version numbers in URLs to manage changes. GraphQL encourages evolving the schema by adding new fields and deprecating old ones without versioning.

❓ query_result

advanced

GraphQL query result shape

Given this GraphQL query:

{ user(id: "1") { name, posts { title } } }

What is the expected shape of the JSON response?

A {"data": {"name": "Alice", "posts": [{"title": "Post 1"}, {"title": "Post 2"}]}}

B {"data": {"user": {"name": "Alice", "posts": [{"title": "Post 1"}, {"title": "Post 2"}]}}}

C {"user": {"name": "Alice", "posts": [{"title": "Post 1"}, {"title": "Post 2"}]}}

D {"data": {"user": {"name": "Alice"}}}

💡 Hint

GraphQL responses always wrap data inside a 'data' key.

GraphQL responses wrap the requested data inside a 'data' object. The shape matches the query structure exactly.

📝 Syntax

advanced

Identify the syntax error in this GraphQL query

Which option contains a syntax error in the GraphQL query?

GraphQL

query { user(id: "1") { name posts { title } } }

A query { user(id: "1") { name, posts { title } } }

B } } } eltit { stsop ,eman { )"1" :di(resu { yreuq

C query { user(id: "1") { name posts { title } } }

D } } } eltit { stsop eman { )"1" :di(resu { yreuq

💡 Hint

Look for missing commas between fields.

GraphQL requires commas between fields in selection sets. Missing commas cause syntax errors.

❓ optimization

expert

Optimizing REST API calls compared to GraphQL

You have a REST API with endpoints /users and /posts. To get a user's name and their posts' titles, you must call both endpoints. How does GraphQL optimize this scenario?

A GraphQL duplicates data in each query to avoid multiple calls.

B GraphQL requires separate queries for user and posts, increasing network calls.

C GraphQL caches REST endpoints internally, so no optimization is needed.

D GraphQL allows fetching user name and posts titles in a single query, reducing network calls.

💡 Hint

Think about how many requests are needed in REST vs GraphQL for related data.

GraphQL lets clients request related data in one query, reducing the number of network calls compared to REST which requires multiple endpoints.