Latest JUnit Interview Questions and Answers

JUnit Interview Questions and Answers

JUnit job has been rapidly getting attention because of immense companies who are seeking talents. So, what is JUnit? JUnit is nothing but a trying structure for unit testing. It utilizes Java as a programming stage, and it is an Open-Source Software oversaw by the people group. It utilizes Java Archive bundle document design during aggregation. The whole bundle structure lives under various names for various renditions. For instance, JUnit 3.8 is JUnit.framework bundle, and for JUnit 4 and later, it is org.JUnit bundle. We will discuss the Latest JUnit Interview Questions and Answers here.

Here are the top target type Junit Interview questions and their answers. These example questions are outlined by specialists who train Junit trainees to give an insight into how one can perfectly answer in an interview. We’re glad to have put these questions, and let’s take a look!

JUnit Interview Questions and Answers

The underneath Junit questions and answers are for freshers and professionals.

  1. Clarify what is Unit Test Case and explain how you can compose a straightforward JUnit experiment? 

Unit Test Case is a piece of the code that guarantees that another piece of code (strategy) carries on true to form. For every prerequisite, there should be, in any event, two experiments, one negative test, and one certain test. 

To compose a JUnit experiment…

  • Decide a subclass of TestCase 
  • To introduce object(s) under test, supersede the setup() strategy 
  • To deliver object(s) under test supersede the teardown() strategy 
  • Decide at least one public test XYZ() strategies that activity the items under test and attest anticipated outcomes. 
  1. What are the significant highlights of JUnit? 

Import highlights of JUnit are: 

  • It is an open-source system. 
  • It gives Annotation to recognize the test techniques. 
  • Gives Assertions to testing anticipated outcomes. 
  • Gives Test sprinters to running tests. 
  • JUnit tests can be run naturally, and they check their outcomes and give prompt input. 
  • JUnit tests can be coordinated into test suites containing experiments and, surprisingly, other test suites. 
  • JUnit shows test progress in a green bar if the test is going fine, and it becomes red when a test fizzle. 
  1. Notice various strategies for special cases taking care of in JUnit? 

There are various strategies for exemption dealing with in JUnit 

  • Attempt get expression 
  • With JUnit rule 
  • With @Test comment 
  • With getting special case library 
  • With customs comment 
  1. Explain what is overlook test in JUnit? 
  • When your code isn’t prepared, and it would come up short whenever executed, you can utilize @Ignore explanation. 
  • It won’t execute a test technique explained with @Ignore 
  • It won’t execute any of the test strategies for the test class on the off chance that it is explained with @Ignore 
  1. When you should run the JUnit test, Is there a specific time stretch between each run? 

No, there is no time requirement. A JUnit test needs to run at whatever point there is an adjustment in the source code. This guarantees that the new change goes through every one of the tests. 

  1. Can we change the return kind of JUnit test technique from void to some other sort? 

Ideally, you ought not to do this. All the JUnit test techniques ought to have a void bring type back. On the off chance that you change the return type, the test strategy would not be considered a test technique and would be overlooked during tests. 

  1. Explain who should utilize JUnit – an engineer or analyzer? Why you use JUnit to test your code?

JUnit is all the more regularly utilized by designers to execute unit tests in JAVA. It is intended for unit testing that is more a coding cycle and not a testing interaction. Be that as it may, numerous analyzers and QA engineers use JUnit for unit testing. JUnit is utilized because 

  • It tests early and mechanizes testing. 
  • JUnit tests can be assembled with the form so that relapse testing should be possible at the unit level. 
  • It permits test code re-utilization 
  • JUnit tests act as a record for the unit tests when there is an exchange. 
  1. Explain what is JUnitCore Class? 

JUnitCore class is an inbuilt class in JUnit bundle; it depends on Façade configuration design, this class is utilized to run just distinct test classes as it were.

  1. Explain mocking and stubbing? Did you utilize any deriding structure? 

Mocking is a component where an article copies like a genuine item. Stubbing is codes that are liable for occurring of another part. There are different distinctive Java ridiculing structures, for example, Mockito, EasyMock, and so on. 

  1. What is the unit test show that you follow? 

The show you follow ought to have each data needed by the strategy name in an organized way. Unit test names should act like the documentation giving an unmistakable thought of what usefulness is tried. Different methods could be utilized to name unit tests. Some of them are the accompanying: Given… When… Then… Should… and so on 

  1. Mention what is the distinction between JUnit and TestNG? 


  • In JUnit, the naming show for comment is somewhat convoluted for, e.g., “Previously,” “After,” and “Anticipated.” 
  • In JUnit, for a technique announcement, you need to follow a particular style like utilizing “@BeforeClass” and “@AfterClass.” 
  • In the JUnit technique name, the imperative is available 
  • JUnit system doesn’t have “Defined Test” or “Reliance Test” include 
  • In JUnit, a gathering of experiments are not accessible 
  • JUnit doesn’t uphold equal execution on Selenium experiments 
  • It can’t re-run the bombed cases 


  • In TestNG, it is more clear explanations like “BeforMethod,” “AfterMethod,” and “ExpectedException.” 
  • In TestNG, there is no limitation like you need to pronounce strategies in a particular configuration 
  • In TestNG strategy, name requirement is absent, and you can decide any test technique names 
  • TestNG use “dependOnMethods” to carry out the reliance testing 
  • In TestNG, a gathering of experiments is accessible 
  • In TestNG Parallel execution of Selenium, experiments are conceivable 
  • It can rerun the bombed tests
  1. How to make Parameterized tests? 

There are five stages to make Parameterized tests:

  • In the first place, the test class is commented on with @RunWith, which is a Parameterized.class. At that point, make a public static strategy that is commented on with @Parameters. It returns a Collection of Objects as a test informational index. 
  • Then, make a public constructor which takes in a single line of test information. 
  • Make a case variable that is for every segment of the test information column. 
  • Make test case(s) utilizing the case factors as a wellspring of the test information. 
  • The experiment summons once per line of information. 
  1. What are the Cactus augmentations? Furthermore, what are its basic parts? 

Cactus is a basic test system. It is for unit testing worker-side java code, for example, servlets, EJBs, and Tag Libs. Cactus can limit the expense of composing tests on worker-side code. It utilizes Junit inside and broadens something similar. How Cactus carries out is through an in-compartment system. 

  1. How to Compile a JUnit Test Class and What occurs if a JUnit Test Method is Declared as “private”? 

Compiling a JUnit test class resembles arranging some other Java classes. The lone thing you need to look out for is that the JUnit JAR document should be remembered for the classpath. 

If a JUnit test strategy is pronounced as “private,” it gathers effectively. However, the execution will fizzle. This is because JUnit necessitates that all test strategies should be proclaimed as “public.” 

  1. What do you comprehend by JWebUnit? What’s more, what are its benefits? 

This is the most famous Junit Interview Questions asked in a meeting. WebUnit is likewise a Java-based testing system to test web applications. It folds over existing testing systems to permit brisk testing of web applications and accompanies a basic testing interface. 

To check the rightness of an application, JWebUnit gives an undeniable level Java API to test a web application alongside many affirmations. This incorporates route through connections and structures section and accommodation. It likewise includes approval of table substance and other regular business web application highlights. The simple route strategies that accompany prepared-to-utilize affirmations consider more fast test creation than utilizing Junit or HtmlUnit as it were. Furthermore, if changing from HtmlUnit to other modules, Selenium is required, there ought to be no compelling reason to revise tests.

  1. What is a test fixture for JUnit? 

A test fixture is otherwise called a regulated state of objects that can be utilized as a stage for running the tests. The basic role is to spread the word about sure that there is an environment where the advancement tests can be run. Different models can be referred to in this specific situation. They are as per the following: 

  • Replicating the fixed, known arrangement of records 
  • Setting up the information and the making of false and phony articles 
  • Surveying an information base with fixed and known arrangements of information 

It is likewise fundamental for you to note that if a gathering of tests has similar fittings, one requirement to compose an alternate arrangement code. If the gathering of evaluations needs an alternate test installation, one can compose the code close by the test method. Thusly, one can make the best frill identified with a test. 

  1. Explain why JUnit just reports the principal disappointment in a solitary endeavor? 

It is intriguing to note that adage different weaknesses in a single endeavor imply that the test is bigger. This is the explanation that JUnit is planned so that it normally runs on a more modest number of tests. Curiously, it is equipped for executing every evaluation inside the limits of a different investigation. Besides, it is additionally ready to report the disappointments on each endeavor of the tests. 

  1. What are the cons of manual testing? 

The disservices of manual testing are as per the following: 

  • Tedious: As experiments are executed by HR, so it is moderate and dreary. 
  • Colossal interest in HR: As experiments should be executed physically, more analyzers are needed in manual testing. 
  • Less solid: It is less dependable as tests may not be performed with precision each time on account of human blunders. 
  • Non-programmable: No programming should be possible to compose complex tests which get disguised information. 
  1. What are the pros of automated testing? 

The benefits are as per the following: 

  • Quick: Automation testing measure is altogether quicker than HR. 
  • Less interest in HR: Test cases are executed by utilizing robotization apparatus, so fewer analyzers are needed in computerization testing. 
  • More dependable: Automation tests carry out absolutely the same activity each time they are run. 
  • Programmable: Testers can program refined tests to get the secret data.
  1. What is a test suite, test runner, and what is the reason for org.JUnit.TestResult class? 

Test suite implies pack a couple of unit experiments and run them together. In JUnit, both @RunWith and @Suite explanation are utilized to run the suite test. The test runner is utilized for executing the experiments. A TestResult gathers the consequences of executing an experiment. It is a case of the Collecting Parameter design. The test structure recognizes disappointments and mistakes. A disappointment is expected and checked for with statements. Mistakes are unforeseen issues like an ArrayIndexOutOfBoundsException.

  1. Would we be able to change the return kind of JUnit test technique from void to some other sort? 

Ideally, you ought not to do this. All the JUnit test techniques ought to have a void bring type back. If you change the return type, the test strategy would not be considered a test technique and would be overlooked during the execution of tests. 

  1. The strategies Get () and Set () ought to be tried for which conditions? 

Unit tests performed on java code ought to be intended to target regions that may break. Since the set() and get() techniques on straightforward information types are probably not going to break, there is no compelling reason to test them expressly. Then again, set() and get() techniques on complex information types are helpless against the break. So they ought to be tried.


JUnit interview can be tough but isn’t impossible to get through. We hope our sample questions with answers aided you and we wish you all the best!

Also read Interview Tips And Examples

Latest JUnit Interview Questions and Answers

Leave a Reply

Your email address will not be published. Required fields are marked *

Scroll to top