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351.

Which of the below is an incorrect annotation with respect to JUnits?(a) @Test(b) @BeforeClass(c) @Junit(d) @AfterEach

Answer» The correct option is (c) @Junit

Best explanation: @Test is used to annotate method under test, @BeforeEach and @AfterEach are called before and after each method respectively. @BeforeClass and @AfterClass are called only once for each class.
Discussion
352.

What is Optional object used for?(a) Optional is used for optional runtime argument(b) Optional is used for optional spring profile(c) Optional is used to represent null with absent value(d) Optional means it’s not mandatory for method to return object

Answer» Correct answer is (c) Optional is used to represent null with absent value

Explanation: Optional object is used to represent null with absent value. This class has various utility methods to facilitate code to handle values as ‘available’ or ‘not available’ instead of checking null values.
Discussion
353.

Which of the following is not introduced with Java 8?(a) Stream API(b) Serialization(c) Spliterator(d) Lambda Expression

Answer» Right option is (b) Serialization

The explanation: Serialization is not introduced with Java 8. It was introduced with an earlier version of Java.
Discussion
354.

What type of methods an interface contain by default?(a) abstract(b) static(c) final(d) private

Answer» Right choice is (a) abstract

Explanation: By default, interface contains abstract methods. The abstract methods need to be implemented by concrete classes.
Discussion
355.

What is the substitute of Rhino javascript engine in Java 8?(a) Nashorn(b) V8(c) Inscript(d) Narcissus

Answer» Correct choice is (a) Nashorn

Best explanation: Nashorn provides 2 to 10 times faster in terms of performance, as it directly compiles the code in memory and passes the bytecode to JVM. Nashorn uses invoke dynamic feature.
Discussion
356.

Which of these is not a mocking framework?(a) EasyMock(b) Mockito(c) PowerMock(d) MockJava

Answer» The correct option is (d) MockJava

Explanation: EasyMock, jMock, Mockito, Unitils Mock, PowerMock and JMockit are a various mocking framework.
Discussion
357.

Which of these can be used to differentiate two or more methods having the same name?(a) Parameters data type(b) Number of parameters(c) Return type of method(d) All of the mentioned

Answer» Right option is (d) All of the mentioned

The best explanation: None.
Discussion
358.

Which of these classes is not part of Java’s collection framework?(a) Maps(b) Array(c) Stack(d) Queue

Answer» The correct option is (a) Maps

Easy explanation: Maps is not a part of collection framework.
Discussion
359.

Which of the below is not a javascript framework for UI?(a) Vaadin(b) AngularJS(c) KendoUI(d) Springcore

Answer» Correct answer is (d) Springcore

For explanation I would say: Springcore is not a javascript framework. It is a comprehensive programming and configuration model for enterprise applications based on java.
Discussion
360.

Which of this interface is not a part of Java’s collection framework?(a) List(b) Set(c) SortedMap(d) SortedList

Answer» Correct option is (d) SortedList

The explanation: SortedList is not a part of collection framework.
Discussion
361.

Which of these return type of hasNext() method of an iterator?(a) Integer(b) Double(c) Boolean(d) Collections Object

Answer» Right choice is (c) Boolean

For explanation: hasNext() returns boolean values true or false.
Discussion
362.

Which of these data type can be used for a method having a return statement in it?(a) void(b) int(c) float(d) both int and float

Answer» Right option is (d) both int and float

To explain I would say: None.
Discussion
363.

Which of this method is given parameter via command line arguments?(a) main()(b) recursive() method(c) Any method(d) System defined methods

Answer» Correct option is (a) main()

To explain: Only main() method can be given parameters via using command line arguments.
Discussion
364.

Which of these class object uses the key to store value?(a) Dictionary(b) Map(c) Hashtable(d) All of the mentioned

Answer» Right choice is (d) All of the mentioned

To explain I would say: Dictionary, Map & Hashtable all implement Map interface hence all of them uses keys to store value in the object.
Discussion
365.

What is the name of a data member of class Vector which is used to store a number of elements in the vector?(a) length(b) elements(c) elementCount(d) capacity

Answer» Right option is (c) elementCount

Best explanation: None.
Discussion
366.

Which of these data types is used to store command line arguments?(a) Array(b) Stack(c) String(d) Integer

Answer» The correct option is (c) String

Easiest explanation: None.
Discussion
367.

Which of these is a class which uses String as a key to store the value in object?(a) Array(b) ArrayList(c) Dictionary(d) Properties

Answer» Right choice is (d) Properties

The explanation is: None.
Discussion
368.

Which of these methods is used to retrieve the elements in properties object at specific location?(a) get()(b) Elementat()(c) ElementAt()(d) getProperty()

Answer» Right answer is (d) getProperty()

Easiest explanation: None.
Discussion
369.

What is true about do statement?(a) do statement executes the code of a loop at least once(b) do statement does not get execute if condition is not matched in the first iteration(c) do statement checks the condition at the beginning of the loop(d) do statement executes the code more than once always

Answer» Right choice is (a) do statement executes the code of a loop at least once

Easiest explanation: Do statement checks the condition at the end of the loop. Hence, code gets executed at least once.
Discussion
370.

From where break statement causes an exit?(a) Only from innermost loop(b) Terminates a program(c) Only from innermost switch(d) From innermost loops or switches

Answer» The correct choice is (d) From innermost loops or switches

For explanation I would say: The break statement causes an exit from innermost loop or switch.
Discussion
371.

What is true about a break?(a) Break stops the execution of entire program(b) Break halts the execution and forces the control out of the loop(c) Break forces the control out of the loop and starts the execution of next iteration(d) Break halts the execution of the loop for certain time frame

Answer» Correct choice is (b) Break halts the execution and forces the control out of the loop

For explanation: Break halts the execution and forces the control out of the loop.
Discussion
372.

Which of the following is not a valid jump statement?(a) break(b) goto(c) continue(d) return

Answer» The correct choice is (b) goto

For explanation I would say: break, continue and return transfer control to another part of the program and returns back to caller after execution. However, goto is marked as not used in Java.
Discussion
373.

Which of these jump statements can skip processing the remainder of the code in its body for a particular iteration?(a) break(b) return(c) exit(d) continue

Answer» Correct option is (d) continue

To elaborate: None.
Discussion
374.

Which of the following loops will execute the body of loop even when condition controlling the loop is initially false?(a) do-while(b) while(c) for(d) none of the mentioned

Answer» Right option is (a) do-while

To elaborate: None.
Discussion
375.

How to remove duplicates from List?(a) HashSet listToSet = new HashSet(duplicateList);(b) HashSet listToSet = duplicateList.toSet();(c) HashSet listToSet = Collections.convertToSet(duplicateList);(d) HashSet listToSet = duplicateList.getSet();

Answer» Correct option is (a) HashSet listToSet = new HashSet(duplicateList);

Explanation: Duplicate elements are allowed in List. Set contains unique objects.
Discussion
376.

If the size of the array used to implement a circular queue is MAX_SIZE. How rear moves to traverse inorder to insert an element in the queue?(a) rear=(rear%1)+MAX_SIZE(b) rear=(rear+1)%MAX_SIZE(c) rear=rear+(1%MAX_SIZE)(d) rear=rear%(MAX_SIZE+1)

Answer» The correct choice is (b) rear=(rear+1)%MAX_SIZE

The explanation is: The front and rear pointer od circular queue point to the first element.
Discussion
377.

What is the difference between Queue and Stack?(a) Stack is LIFO; Queue is FIFO(b) Queue is LIFO; Stack is FIFO(c) Stack and Queue is FIFO(d) Stack and Queue is LIFO

Answer» Right answer is (a) Stack is LIFO; Queue is FIFO

To explain: Stack is Last in First out (LIFO) and Queue is First in First out(FIFO).
Discussion
378.

What are the use of front and rear pointers in CircularQueue implementation?(a) Front pointer points to first element; rear pointer points to the last element(b) Rear pointer points to first element; front pointer points to the last element(c) Front and read pointers point to the first element(d) Front pointer points to the first element; rear pointer points to null object

Answer» Right answer is (c) Front and read pointers point to the first element

For explanation: CircularQueue implementation is an abstract class where first and rear pointer point to the same object.
Discussion