REST vs SOAP vs GraphQL comparison in Rest API - Practice Questions

Challenge - 5 Problems

🧠 Conceptual

intermediate

Key difference in data fetching between REST and GraphQL

Which statement best describes how REST and GraphQL differ in data fetching?

A REST allows clients to specify exactly what data they want, GraphQL fetches fixed data per endpoint.

B REST fetches fixed data per endpoint, GraphQL allows clients to specify exactly what data they want.

C Both REST and GraphQL always fetch all data from the server regardless of client request.

D REST and GraphQL both require multiple requests to fetch related data.

💡 Hint

Think about how flexible the client is in choosing data with each approach.

REST endpoints return fixed data structures, while GraphQL queries let clients specify exactly which fields they want.

❓ Predict Output

intermediate

Output of a SOAP fault response

What is the output when a SOAP service returns a fault response with this XML snippet?

Rest API

<?xml version="1.0"?>
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
  <soap:Body>
    <soap:Fault>
      <faultcode>soap:Client</faultcode>
      <faultstring>Invalid request</faultstring>
    </soap:Fault>
  </soap:Body>
</soap:Envelope>

A A timeout error from the server.

B A successful response with requested data.

C A syntax error in the SOAP message.

D An error indicating 'Invalid request' with fault code 'soap:Client'.

💡 Hint

Look at the element and its children.

The element signals an error. The faultcode and faultstring describe the error details.

❓ Predict Output

advanced

GraphQL query result for nested data

Given this GraphQL query, what is the expected JSON response?

Rest API

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

A { "data": { "user": { "name": "Alice", "posts": [ { "title": "Hello", "comments": [ { "text": "Nice post!" } ] } ] } } }

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

C { "error": "Field 'posts' not found" }

D { "data": { "user": null } }

💡 Hint

GraphQL returns exactly the fields requested, including nested objects.

The query asks for user name, posts with titles, and comments with text, so the response includes all nested data.

🧠 Conceptual

advanced

SOAP vs REST protocol characteristics

Which of these is true about SOAP compared to REST?

A SOAP is stateless and uses JSON only, REST is stateful and uses XML only.

B SOAP is simpler and faster than REST for all use cases.

C SOAP uses XML and has built-in standards for security and transactions, REST is more flexible and uses multiple formats.

D SOAP does not support encryption, REST always requires encryption.

💡 Hint

Think about the protocol and message format differences.

SOAP is a protocol with strict standards and XML messages; REST is an architectural style supporting multiple formats and is more flexible.

🧠 Conceptual

expert

Choosing API style for complex client-driven data needs

A mobile app needs to fetch complex, nested data but wants to minimize the number of requests and data size. Which API style is best suited?

A GraphQL, because it allows clients to request exactly the nested data they need in one request.

B SOAP, because it uses XML which is smaller and faster than JSON.

C REST, because it requires multiple endpoints and requests for nested data.

D None, because all API styles require multiple requests for nested data.

💡 Hint

Consider how each API style handles nested data and request flexibility.

GraphQL lets clients specify nested data in one query, reducing requests and data size. REST often requires multiple calls, SOAP is verbose.