100 Top API Testing Job Interview Questions and Answers

API Testing Interview Questions with Answers:-

1. What is API testing?

API (Application Programming Interface) specifies how some software components should interact with other, in other words, it’s a set of functions and procedures that allows the creation of applications which access the features or data of an application or operating system. Testing of these functions is known as API testing.

2. What are the tools used for API testing?

The tools used for various API testing are

  • SoapUI Pro
  • PostMan
  • Alertsite API monitoring

3. What are the commonplace tests carried out on API’s?

  • The not unusual exams achieved on API’s
  • Verification of the API whether it’s miles updating any records structure
  • Verify if the API does not go back something
  • Based on input conditions, returned values from the API’s are checked
  • Verification of the API whether it triggers a few different occasion or calls every other API

4. Point out the important thing difference among UI level testing and API trying out?

UI ( consumer Interface) refers to trying out graphical interface such as how a person interacts with the applications, testing utility elements like fonts, photos, layouts, etc. UI checking out basically specializes in look and feel of the software.

Whilst, API allows conversation between separate software structures. A software gadget imposing an API includes features or sub-workouts that can be performed by way of some other software program machine

5. Provide an explanation for what is cleaning soap?

Soap-stands for easy item access manage, and it’s far an XML primarily based protocol for replacing information among computer systems.

6. Provide an explanation for API framework?

API framework is self-explanatory. Values for a test run and for holding the configurable elements, config record is used. automatic check cases have to represent in “ parse-desk” format within the config file. whilst trying out API, it isn’t always essential to test every API so the config record has some segment whose all API is activated for that precise run.

7. How does the API Builder work?

  1. API Builder is a PLSQL software includes 4 square files
  2. For placing API parameters and beginning the technique one report is responsible
  3. files are created for brief tables and master bundle to create the outputted code
  4. The fourth record creates “spooled” output of the code into a record referred to as “output_script_.sq.”

8. Explain what’s TestApi?

TestApi is a library of software and checks APIs that allows testers and developers to create checking out gear and automatic assessments for .internet and Win32 utility. It gives a set of not unusual test building blocks, sorts, data-shape, and algorithms.

9. What’s input injection and what are different methods of doing it?

Input Injection: it’s miles the act of simulating user enter, in several ways you may simulate user input.

  • Direct Method Invocation
  • Invocation using an accessibility interface
  • Simulation using low-degree input
  • Simulation the usage of a tool motive force
  • Simulation the usage of a robot

10. What is the principle demanding situations of API testing?

The principal challenges in API trying out is

  1. Parameter selection
  2. Parameter aggregate
  3. Name sequencing

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11. What is API checking out with run score?

Runscope is an internet application that gives backend offerings and easy to use interface for testing APIs.

12. Explain what are the principles of API take a look at the design?

The principle for API test layout is

Setup: Create items, begin services, initialize records, etc

Execution: Steps to exercising API or state of affairs, additionally logging

Verification: Oracles to assess execution final results

Reporting: skip, failed or blocked

easy up: Pre-check nation

13. What is the equipment used for API check automation?

While trying out Unit and API checking out, each goal source code, if an API technique is using code based on .internet then the tool that is assisting have to have .internet

Automation tools for API trying out can be used are

  • NUnit for .internet
  • JUnit for Java
  • HP UFT
  • soap UI

14. Point out the steps for testing API?

API checking out steps

  1. Choose the take a look at a case that needs to be fulfilled
  2. For API call develop a check case
  3. To satisfy the take a look at case configure the API parameters
  4. Decide how will you validate a successful take a look at
  5. The usage of programming languages like PHP or .net execute the API call
  6. Permit the API name to return the information to validate

15. What are the common protocols which are checking out in API testing?

  • HTTP
  • JMS
  • REST
  • SOAP
  • UDDI

16. Give an explanation for in brief the exceptional sorts of output determined of an API.

API is taken into consideration as the critical connecting part of this virtual global. It basically resides in the business logic layer in which it performs capabilities like processing commands, application coordination, initiates logical decisions, and so on.

The main attention is returning correct effects beneath any type of situations. especially, the output or consequences located of an API are divided into 3 sections as follows:

  • Returning the end result reputation values as ‘skip’ or ‘Fail’.
  • Result as statistics or any particular records.
  • An event wherein the decision to any API characteristic will initiate the call to another API feature.

17. What is the equipment used for API take a look at automation?

Automation trying out is a have to while we speak about agile improvement in API checking out. however, the language wherein the code is written is also a vital thing because it makes a decision the tool language.

let us see some important API take a look at automation tools:

SOAPUI: it’s for an open source API testing tool that’s taken into consideration because the pleasant checking out device due to its feature like growing complex validation scripts and check instances, efficient check insurance, etc.

HP QTP/UFT: this is now referred to as HP UFT i.e. unified practical trying out. This device is essentially used for systems without consumer interfaces like internet offerings, and many others.

PARASOFT: This testing device runs on diverse platforms and is used to test API which does not have a Graphical user interface (GUI).

18. Enlist some of the API examples which can be very widely recognized and famous.

There are numerous such examples, enlisted underneath are a few maximum famous ones:

Google Maps API: these are designed in particular for mobile and laptop use with the assist of the flash interface and JavaScript.

Amazon advertising API: Amazon is thought for their products and as a result, their advertising and marketing API accesses their product to find out their functionality and for that reason put it up for sale hence.

Twitter: The API for twitter is usually in classes, one for accessing records and the opposite for interacting with Twitter seek.

YouTube: This API used for YouTube includes various functionalities together with films, live streaming, player, etc.

19. What’s TestApi?

TestApi is known as the library of test building blocks which are vital for builders and testers for creating trying out equipment as well as computerized check suites.

20. What are the types of Bugs will API testing finds?

The types of Bugs, API will find

  • Missing or duplicate functionality
  • Fails to handle error conditions gracefully
  • Stress
  • Reliability
  • Security
  • Unused flags
  • Not implemented errors
  • Inconsistent error handling
  • Performance
  • Multi-threading issues
  • Improper errors