REST API follows a strict protocol similar to SOAP, which mandates specific messaging formats.

• True

• False

Answer explanation

REST is not a strict protocol but a set of architectural constraints. It is more flexible than SOAP, which has specific XML-based messaging rules.

JSON is the most commonly used format for REST API communication because it is lightweight and easy to read.

• True

• False

Answer explanation

JSON is widely used due to its simplicity, readability, and compatibility with multiple programming languages.

An API data contract defines the structure and constraints of data exchanged between the API provider and consumer.

• True

• False

Answer explanation

API data contracts specify the expected request and response formats, ensuring consistency.

REST APIs are stateful, meaning they store client session information between requests.

• True

• False

Answer explanation

REST APIs are stateless, meaning each request is independent and does not rely on stored session data.

A ‘401 Unauthorized’ error indicates that the request was malformed and could not be understood by the server.

• True

• False

Answer explanation

A 401 Unauthorized error means the request lacks valid authentication credentials. A 400 Bad Request error would indicate a malformed request.

REST APIs support multiple HTTP methods, including GET, POST, PUT, DELETE, and PATCH.

• True

• False

Answer explanation

These methods define different operations, such as retrieving, creating, updating, and deleting resources.

API versioning is necessary when introducing breaking changes to maintain backward compatibility.

• True

• False

Answer explanation

Versioning ensures that existing clients can continue using older versions while new features are introduced.

Which of the following best defines a REST API?

• A tool for debugging software

• A method for manual testing

• A set of constraints for designing web services

• A graphical interface for application users

Answer explanation

REST (Representational State Transfer) is a set of architectural constraints used for designing APIs, not a tool or user interface.

Which key principle makes REST APIs stateless?

• API calls always require user authentication

• Each request is processed independently

• The server maintains session history

• REST APIs use XML instead of JSON

Answer explanation

REST APIs do not store client state between requests, making them stateless. Each request must contain all necessary information.

What does an API data contract specify?

• The types of data an API can accept and return

• The visual design of an API

• The security level of an API

• The number of requests an API can handle

Answer explanation

API data contracts define the expected request and response formats, ensuring compatibility between API consumers and providers.