Java Programming MCQ (Multiple Choice Questions) - SchoolingAxis

Java Programming MCQ (Multiple Choice Questions)

 Que-  What is the worst case complexity of accessing an element in ArrayList?

a. O(n)

b. O(1)

c. O(nlogn)

d. O(2)


Answer- O(1)


Que-  When an array is passed to a method, will the content of the array undergo changes with the actions carried within the function?

a.TRUE

b.FALSE

c.Nothing Can be Said

d.None of the mentioned


Answer-TRUE


Que-  What is the default clone of HashSet?

a. Deep clone

b. Shallow clone

c. Plain clone

d. Hollow clone


Answer- Shallow clone


Que-  Do we have get(Object o) method in HashSet.

a.TRUE

b.FALSE

c.Nothing Can be Said

d.None of the mentioned


Answer-FALSE


Que-  What does Collections.emptySet() return?

a. Immutable Set

b. Mutable Set

c. The type of Set depends on the parameter passed to the emptySet() method

d. Null object


Answer- Immutable Set


Que-  What are the initial capacity and load factor of HashSet?

a. 10, 1.0

b. 32, 0.75

c. 16, 0.75

d. 32, 1.0


Answer- 16, 0.75


Que-  What is the relation between hashset and hashmap?

a. HashSet internally implements HashMap

b. HashMap internally implements HashSet

c. HashMap is the interface; HashSet is the concrete class

d. HashSet is the interface; HashMap is the concrete class


Answer- HashSet internally implements HashMap


Que-  What is the difference between TreeSet and SortedSet?

a. TreeSet is more efficient than SortedSet

b. SortedSet is more efficient than TreeSet

c. TreeSet is an interface; SortedSet is a concrete class

d. SortedSet is an interface; TreeSet is a concrete class


Answer- SortedSet is an interface; TreeSet is a concrete class


Que-  What happens if two threads simultaneously modify TreeSet?

a. ConcurrentModificationException is thrown

b. Both threads can perform action successfully

c. FailFastException is thrown

d. IteratorModificationException is thrown


Answer- ConcurrentModificationException is thrown


Que-  What is the unique feature of LinkedHashSet?

a. It is not a valid class

b. It maintains the insertion order and guarantees uniqueness

c. It provides a way to store key values with uniqueness

d. The elements in the collection are linked to each other


Answer- It maintains the insertion order and guarantees uniqueness


Que-  Which of these standard collection classes implements a linked list data structure?

a. AbstractList

b. LinkedList

c. HashSet

d. AbstractSet


Answer- LinkedList


Que-  Which of these classes implements Set interface?

a. ArrayList

b. HashSet

c. LinkedList

d. DynamicList


Answer- HashSet


Que-  Which of these method is used to add an element to the start of a LinkedList object?

a. add()

b. first()

c. AddFirst()

d. addFirst()


Answer- addFirst()


Que-  Which of these method of HashSet class is used to add elements to its object?

a. add()

b. Add()

c. addFirst()

d. insert()


Answer- add()


Que-  Which of these methods can be used to delete the last element in a LinkedList object?

a. remove()

b. delete()

c. removeLast()

d. deleteLast()


Answer- removeLast()


Que-  Which of this method is used to change an element in a LinkedList Object?

a. change()

b. set()

c. redo()

d. add()


Answer- set()


Que-  Which of these standard collection classes implements a linked list data structure?

a. AbstractList

b. LinkedList

c. HashSet

d. AbstractSet


Answer- LinkedList


Que-  Which of these classes implements Set interface?

a. ArrayList

b. HashSet

c. LinkedList

d. DynamicList


Answer- HashSet


Que-  Which of these method is used to add an element to the start of a LinkedList object?

a. add()

b. first()

c. AddFirst()

d. addFirst()


Answer- addFirst()


Que-  Which of these method of HashSet class is used to add elements to its object?

a. add()

b. Add()

c. addFirst()

d. insert()


Answer- add()


Que-  Which of these methods can be used to delete the last element in a LinkedList object?

a. remove()

b. delete()

c. removeLast()

d. deleteLast()


Answer- removeLast()


Que-  Which of this method is used to change an element in a LinkedList Object?

a. change()

b. set()

c. redo()

d. add()


Answer- set()


Que-  Which of these object stores association between keys and values?

a. Hash table

b. Map

c. Array

d. String


Answer- Map


Que-  Which of these classes provide implementation of map interface?

a. ArrayList

b. HashMap

c. LinkedList

d. DynamicList


Answer- HashMap


Que-  Which of these method is used to remove all keys/values pair from the invoking map?

a. delete()

b. remove()

c. clear()

d. removeAll()


Answer- remove()


Que-  Which of these method Map class is used to obtain an element in the map having specified key?

a. search()

b. get()

c. set()

d. look()


Answer- get()


Que-  Which of these methods can be used to obtain set of all keys in a map?

a. getAll()

b. getKeys()

c. keyall()

d. keySet()


Answer- keySet()


Que-  Which of these method is used add an element and corresponding key to a map?

a. put()

b. set()

c. redo()

d. add()


Answer- put()

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