Java Unit Test MCQ

 Question 1

Which framework is most commonly used for unit testing in Java?

JUnit  

TestNG  

Mockito  

Selenium

Answer:  

JUnit

Question 2

In JUnit 5, which annotation is used to indicate a test method?

@TestCase  

@RunWith  

@Test  

@Before

Answer:  

@Test

Question 3

Which JUnit annotation is used to execute some code before each test method?

@BeforeAll  

@After  

@BeforeEach  

@BeforeTest

Answer:  

@BeforeEach

Question 4

Which method in JUnit is used to check if two objects are equal?

assertSame  

assertTrue  

assertEquals  

assertNotNull

Answer:  

assertEquals

Question 5

Which of the following is a mocking framework often used in Java unit tests?

TestNG  

Mockito  

JUnit  

Cucumber

Answer:  

Mockito

Question 6

In Mockito, which method is used to create a mock object?

mock()  

createMock()  

mockObject()  

newMock()

Answer:  

mock()

Question 7

What does the @Mock annotation do in Mockito?

It creates a real object  

It creates a mock object  

It verifies a method call  

It initializes a mock object

Answer:  

It creates a mock object

Question 8

Which JUnit annotation is used to run a piece of code after all tests in the test class have been run?

@AfterEach  

@AfterAll  

@AfterTest  

@After

Answer:  

@AfterAll

Question 9

In TestNG, which annotation is equivalent to JUnit's @BeforeEach?

@BeforeTest  

@BeforeMethod  

@BeforeClass  

@BeforeSuite

Answer:  

@BeforeMethod

Question 10

Which Mockito method is used to verify that a method was called with specific arguments?

verify()  

check()  

assert()  

confirm()

Answer:  

verify()

Question 11

In JUnit 5, which annotation is used to disable a test method?

@Ignore  

@Disabled  

@Skip  

@Deactivate

Answer:  

@Disabled

Question 12

Which of the following is not a lifecycle method in JUnit 5?

@BeforeEach  

@AfterEach  

@BeforeClass  

@BeforeAll

Answer:  

@BeforeClass

Question 13

Which of the following assertions is used to check if a condition is false in JUnit?

assertTrue()  

assertFalse()  

assertNull()  

assertNotNull()

Answer:  

assertFalse()

Question 14

What is the primary purpose of unit testing?

To test the entire application as a whole  

To test individual units or components in isolation  

To test the user interface  

To test the performance of the application

Answer:  

To test individual units or components in isolation

Question 15

In Mockito, which method is used to return a specific value when a method is called?

when().thenReturn()  

doReturn().when()  

mock().thenReturn()  

verify().thenReturn()

Answer:  

when().thenReturn()

Question 16

Which JUnit annotation is used to provide a timeout for a test method?

@Timeout  

@Test(timeout = 1000)  

@TimeLimit  

@Test(timeout = 1)

Answer:  

@Timeout

Question 17

Which of the following is not a valid JUnit assertion?

assertEquals()  

assertNotNull()  

assertThrows()  

assertEmpty()

Answer:  

assertEmpty()

Question 18

Which JUnit 5 annotation is used to run a test multiple times?

@Repeat  

@RepeatedTest  

@LoopTest  

@TestRepeat

Answer:  

@RepeatedTest

Question 19

In TestNG, which annotation is used to indicate that a method should be executed before any test methods in the current class?

@BeforeTest  

@BeforeClass  

@BeforeMethod  

@BeforeSuite

Answer:  

@BeforeClass

Question 20

In Mockito, how can you mock a method to throw an exception?

when(methodCall).thenThrow(new Exception())  

doThrow(new Exception()).when(methodCall)  

throwException(new Exception()).when(methodCall)  

when(methodCall).throw(new Exception())

Answer:  

when(methodCall).thenThrow(new Exception())