“Top 10 API Testing Important Interview Questions”: Web Service Testing, Rest API.

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Introduction:

Here are some important API testing interview questions and their answers: you can go through this article and you will crack any API related Interview’s. This will be helpful for any fresher or 3-5 years of experienced candidate.

Top 10 Q/A:

1. What is API testing?

  • Answer: API (Application Programming Interface) testing is a type of software testing that focuses on verifying the functionality and performance of APIs. It involves testing the communication between different software systems by sending requests and evaluating the responses.

2. Explain the difference between SOAP and REST APIs.

  • Answer: SOAP (Simple Object Access Protocol) is a protocol for exchanging structured information in web services, often using XML. REST (Representational State Transfer) is an architectural style for designing networked applications. REST APIs use standard HTTP methods (GET, POST, PUT, DELETE) and can return data in various formats (JSON, XML).

3. What is an endpoint in API testing?

  • Answer: An endpoint is a specific URL or URI (Uniform Resource Identifier) that an API exposes for accessing its resources. It represents the location where the API can be accessed, and each endpoint corresponds to a specific function or service provided by the API.

4. Explain the purpose of HTTP methods in API testing.

  • Answer: HTTP methods (GET, POST, PUT, DELETE, etc.) define the operations that can be performed on a resource. GET is used to retrieve data, POST to create data, PUT to update data, and DELETE to remove data. These methods provide a standardized way for clients to interact with the API.

5. What is the significance of status codes in API responses?

  • Answer: Status codes in API responses indicate the success or failure of a request. For example, 200 OK indicates success, 404 Not Found means the requested resource was not found, and 500 Internal Server Error indicates an issue on the server side.
API Testing

6. How do you handle authentication in API testing?

  • Answer: Authentication in API testing is often handled using API keys, OAuth tokens, or other authentication mechanisms. Testers need to include the required authentication details in the API requests to ensure proper access.

7. What is the role of headers in API requests?

  • Answer: Headers in API requests provide additional information about the request, such as content type, authorization details, and caching directives. They help in controlling the behavior of the API request and response.

8. Explain the concept of parameterization in API testing.

  • Answer: Parameterization involves using variables or data placeholders in API requests. This allows testers to execute the same test with different sets of data, helping to validate the API’s behavior under various conditions.

9. What is API mocking, and why is it used in testing?

  • Answer: API mocking involves creating a simulated version of an API to mimic its behavior. It is used in testing to simulate API responses and test different scenarios without relying on the actual API. This is particularly useful during the development phase when the actual API may not be available.

10. How do you ensure the security of APIs during testing?

  • Answer: API security testing involves checking for vulnerabilities such as injection attacks, improper authentication, and data exposure. Testers use tools like OWASP ZAP or perform manual testing to identify and address potential security issues.

Conclusion:

These questions cover a range of topics related to API testing, and candidates should be prepared to discuss their practical experience and problem-solving skills in addition to theoretical knowledge. I hope this article will help you to crack interview.