Web API Interview Questions and Answers

Ques 21. Explain the concept of Bearer token authentication in Web APIs.

Bearer token authentication involves including a token (commonly a JWT) in the 'Authorization' header of the HTTP request. The server validates the token to authenticate the user and authorize the requested action.

Example:

Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c

Ques 22. What is the role of API documentation, and how does it contribute to the development process?

API documentation serves as a guide for developers on how to use and integrate with an API. It provides information on endpoints, request/response formats, authentication, and examples, making it crucial for developers to understand and implement the API correctly.

Ques 23. Explain the concept of idempotency in the context of Web API methods.

An idempotent operation produces the same result whether it is applied once or multiple times. In the context of Web APIs, HTTP methods like GET, PUT, and DELETE are expected to be idempotent, ensuring consistent behavior regardless of the number of requests.

Ques 24. What are the advantages and disadvantages of using JSON Web Tokens (JWT) for authentication in Web APIs?

Advantages include statelessness, compactness, and ease of implementation. Disadvantages may include potential security risks if not properly implemented, and the inability to revoke tokens before expiration.

Ques 25. Explain the purpose of the '204 No Content' HTTP status code.

The '204 No Content' status code indicates a successful request, but there is no additional information to send in the response payload. It is commonly used for operations where a response body is not necessary.