REST API testing interview questions will help prepare you for future interviews. This Blog provides some general REST API testing interview questions, encompassing REST API interview and Java REST API interview questions.

RESTful architecture patterns have become the preferred approach to web service development in recent years. REST APIs utilize HTTP to send and receive data over the web and often follow this trend.

An API endpoint is one of the cornerstones of a REST API and serves as a point where clients can use to gain access to specific resources or take specific actions on servers.

REST API endpoints typically feature a resource identifier and set of query parameters to allow clients to specify actions to take and data to include with requests.

1. What is an Application Programming Interface (API)?

An API is a set of protocols, routines, and tools that allow different software applications to communicate with each other, it acts as an interface between the client and server and enables data exchange between the two.

2. Define the Rest API?

The Rest API is a lightweight, lightweight API that allows users to access and interact with the API within seconds. It is an architectural design that creates APIs, and there are specific rules to follow.

3. What is the purpose of layer systems architecture in REST API?

Layer systems architecture allows an application to be most able by limiting component behaviour, promoting scalability, and enhancing application security.

4. How does API fit into end-to-end project architecture?

API plays a crucial role in end-to-end project architecture by addressing design issues and problems in API testing scenarios, it simplifies the building of client-side software and acts as a communication protocol between the client and server.

5. Explain the character of API testing in web applications?

API testing is necessary for web applications to ensure that they are getting the correct response from the API, it ensures that the integration part of data collection is working correctly and minimizes the risk of problems such as random numbers or incorrect reservation views.

6. What is the front-end interface in a website?

The front-end interface is the part of a website that is designed using a client-side programming language like HTML, CSS, and JavaScript.

7. What does website back-end code do?

The back-end code is responsible for processing reservation details and generating reservation numbers, it communicates with the front-end interface and the database to retrieve and store information.

8. What is the role of the database in a website?

The database stores reservation information and is used to retrieve reservations from clients.

9. How does API work?

API works by receiving information over the HTTP protocol and using JSON or XML format to create reservations.

The developer creates the API in a way that automatically captures the information when a user hits the API.

10. What is the difference between REST and SOAP APIs?

REST APIs are lightweight and flexible, while SOAP APIs have many conditions, restrictions, and tight authorization authentication requirements.

Most legacy services are relied on SOAP due to their lightweight and flexible coding.

11. What is the get method used for in the Rest API?

The get method is used to retrieve information from the server.

12. Explain the variance between the get and post methods in the Rest API?

The post method is used to send data to servers when creating new reservations or updating existing ones, while the get method is used to retrieve information from the server.

13. How do park and covariance parameters differ?

Park parameters are variable parts that change for every API request, while covariance parameters are path parameters to specific resources within a collection.

14. How does Amazon Web Services (AWS) send Amazon.com requests?

AWS is a collection of all orders, and when a request is sent to AWS, it is a query parameter that is used to sort or filter resources.

In contrast, path parameters are used to drill down to specific sub-resources.

15. Explain the aim of using query parameters in AWS?

Query parameters are used to filter or sort existing resources.

16. Why do AWS path parameters exist?

Path parameters are used to drill down to specific sub-resources.

17. How are AWS query and path parameters different?

Query parameters are used to filter or sort existing resources, while path parameters are used to drill down to specific sub-resources.

18. What is Headers’ capacity in AWS?

Headers play a key role in the AWS process, providing additional data needed for authentication or processing the request.

19. What does Postman tool do in API testing?

The Postman tool helps in testing API methods like get, put, and delete.

20. Why is getPlace() API used in the response?

The getPlace() API is used to retrieve the added details.

21. Explain agetPlace() API query parameter’s job?

The query parameters are sent as part of the URL, and the body only comes into view if the request is a get request.

22. Define the benefits of using the put API in Java?

The put API is designed to update only the address field, making it easier to update all fields.

23. What are API client and server roles?

In API, a client is a software application that requests resources from a server, and the server fetches the resource from its database and returns a response.

24. What types of testing involved in API testing?

The different types of testing involved in API testing are web testing, mobile app testing, performance testing, and security testing.

25. Why is client and server concept important in web applications?

Understanding client and server concepts is crucial when working with web-based applications. Clients are users who can access the application through a browser, while servers are the actual application that runs on the server.

Understanding these concepts is essential for effective web application development and maintenance.

26. Explain client application?

A client application is a software program that is responsible for browsing data from a browser.

27. What is a database layer?

A database layer is the part of the system that stores actual data.

28. Define business logic layer?    

A business logic layer is the part of the system that contains business logic, which is responsible for processing requests and sending responses.

29. What are the three main components of a web application?

The three main components of a web application are the presentation layer, application layer, and data layer.

30. What is the three-layer architecture of a web application?

The three layers of a web application are the presentation layer, middle layer, and backend application.

31. Explain about presentation layer?

The presentation layer is the part of the web application that receives requests and sends responses.

32. What is the middle layer?

The middle layer is the part of the web application that handles business logic and APIs.

33. Define the backend application?

The backend application is the part of the web application that handles data storage and processing.

34. What is web testing?

Web testing is the process of testing a web application using Selenium.

35. Define the main goal of API testing?

The main goal of API testing is to reduce time and resources by directly testing the API functionality.

36. Explain the variation between pure APIs and rest APIs?

Pure APIs are related to object access protocols, while rest APIs (resties) are representational state of transfer.

37. What distinguishes API from web service?

All web services are APIs, but not all APIs are web services. Once the API is developed, tested, and made available for public access, it becomes a web service.

38. How are XML and JSON different?

XML is a lengthy and complex data format, while JSON is a lightweight data format.

39. What is the disparity between Html and text?

Html is a markup language used to create web pages, while text is a plain text format.

40. Why is REST different from REST API?

REST API is a specific type of API that supports various types of data, such as XML, JSON, Html, and text.

REST is a general term for any type of architecture that uses HTTP to communicate between different applications.

41. What are the four types of REST API methods?

The four types of REST API methods are GET, POST, PUT, and DELETE.

42. Explain GET request in REST API?

A get request is sent to retrieve data from a site.

43. What is a REST API’s POST request?

A post request is sent to create a database server.

44. What is the diversity between HTTP and HTTPS?

HTTP is a more secure protocol, as data is sent in encrypted format, reducing the risk of hacking.

HTTPS ensures data is transported through the network in encrypted format, ensuring data is not sent in the disaster format.

45. Define the aim of URL in API testing?

Understanding the U R L terminologies is essential for successful API testing.

46. What is RESTful API?

RESTful API refers to conforming to the REST constraints.

47. What function does understanding RESTful API response codes play?

Understanding different types of responses codes is essential for testing the same request through a browser and validating the response data.

48. Which character does the endpoint play in RESTful API testing?

The endpoint is the part of the system that stores the server data. It is the part of the system that stores the data from the host.

49. What discriminates RESTful API single user data and list users API?

Single user data is sent as an API slash users slash two, while the list users API starts all available users in the database.

The list users API response data is in JSON format, including user email, first name, and last name.

50. Explain the aim of the payload in RESTful API testing?

The payload is the data sent through the request and received from the response.

51. What is a put request in a web application?

A put request is used to update a resource on a server.

52. Explain delete request in a web application?

A delete request is used to delete a specified resource on a server and requires an ID.

53. Define endpoint in REST API?

An endpoint is the URI or URL that HTTP requests are sent to.

54. What is authentication in REST API?

Authentication is used to ensure that only authorized clients can access resources on a server. It typically involves getting an access token and sending it with requests.

55. Explain OAuth in authentication?

OAuth is a method for authentication that involves getting an access token and sending it with requests.

56. What is Curl in transferring data?    

Curl is a tool that can transfer data using multiple protocols, including HTTP.

57. Why does REST API use XML?

The XML format is a hierarchical data structure that allows for the return of data in a simple manner.

58. Why do REST API HTTP methods exist?

The HTTP methods (get, port, post, delete) are used to get, find, delete, and update customer information.

59. What does the get method do to display server data?

The get method is used to retrieve data from the server.

60. What is the motive of using various HTTP methods in communicating with clients and servers?

The various HTTP methods are used to understand how a request from the client is processed by the server and how the server sends back the response.

Enhance Your learning with MCQ’s on REST API

1. What is the role of API in end-to-end project architecture?

a) Handle various data types, such as destination dates, names, and room details
b) Simplify the building of client-side software
c) To act as an interface between client and server
d) Address design issues and problems in A P I testing scenarios

2. What is the front-end interface of a website designed using Java?

a) Client-side
b) Back-end
c) Both client-side and back-end
d) Neither client-side nor back-end

3. What is the back-end code responsible for in a website designed using Java?

a) Displaying reservation details on the front-end interface
b) Generating reservation numbers
c) Reservation database processing and availability confirmation
d) Simplify the communication between client and server

4. What is the PUT method in a REST API?

a) Send data to servers when creating new reservations or updating existing ones
b) Capture reservation details when Hotels.com passes the reservation ID
c) Replaces existing resources on the server
d) It is not used in REST APIs

5. What is the importance of understanding the rules of REST APIs?

a) Ensure the API works as expected
b) Send data to servers when creating new reservations or updating existing ones
c) Replace existing resources on the server
d) Capture reservation details when Hotels.com passes the reservation ID

6. What is Amazon Web Services (AWS)?

a) All orders are provided to AWS as a query parameter to sort or filter resources.
b) A tool that helps in testing A P I methods like get, put, and delete
c) An architectural design that creates APIs
d) An API that captures reservation details when Hotels.com passes the reservation ID

7. What is the importance of headers in AWS?

a) Providing additional data needed for authentication or processing the request
b) Capturing reservation details when Hotels.com passes the reservation ID
c) Replacing existing resources on the server
d) Drilling down to specific sub-resources

8. What is the purpose of using the put place API in Java to update a place?

a) Add a new place
b) Update an existing place
c) Retrieve the status message indicating successful HTTP response
d) To retrieve the added place details, such as latitude, longitude, and name

9. What is the architecture of the two-day architecture?

a) Client-server architecture
b) Three-tier architecture
c) N-tier architecture
d) One-tier architecture

10. How many components are there in the three-tier architecture?

a) Two components
b) Three components
c) Four components
d) Five components

11. Which component of a web application is responsible for processing requests and sending responses?

a) Presentation layer
b) Application layer
c) Data layer
d) Business logic layer

12. Which scripting language is used for developing web applications?

a) Html
b) JavaScript
c) C#
d) Java

13. Which layer of a web application handles processing and sends data from the same request to the data layer?

a) Presentation layer
b) Application layer
c) Middle layer
d) Backend application

14. Which technology is used for testing web applications?

a) SQL
b) Java
c) Selenium
d) Python

Conclusion:

REST APIs have become an indispensable element of modern software development, and automating their testing and deployment are crucial to ensure their reliability and performance.

In this blog we have highlighted an assortment of REST API automation interview questions and answers with an emphasis on experienced candidates.

This Blog covered topics related to REST API automation including its basics, testing strategies, deployment/monitoring tools and best practices. Furthermore, specific technologies/frameworks such as Java that are frequently employed for REST API automation were discussed as well as possible automation solutions.

REST API automation is an essential skill for software engineers and developers working with APIs, and candidates who prepare themselves thoroughly and confidently for REST API interview questions can show their proficiency by answering confidently in an interview setting – giving employers confidence they possess this area and position themselves for career success in this competitive job market.