Java - Computer Science Practice Questions and Answers

11

Question 11 of 30

Which of the following is NOT a feature of Java?

Platform Independence

Object-Oriented

Use of Pointers

Multithreading

12

Question 12 of 30

What will be the output of: String s1 = "Java"; String s2 = "Java"; System.out.println(s1 == s2);

true

false

Compilation Error

Runtime Exception

13

Question 13 of 30

Which collection allows duplicate elements and maintains insertion order?

HashSet

TreeSet

ArrayList

HashMap

14

Question 14 of 30

What is the difference between final, finally, and finalize?

All are keywords

final is keyword, others are methods

final and finally are keywords, finalize is method

All are methods

15

Question 15 of 30

Which of these creates an immutable object in Java?

ArrayList

StringBuilder

String

Vector

16

Question 16 of 30

What will happen if you try to access a static method using an instance of the class?

Compilation Error

Runtime Exception

Works fine but not recommended

NullPointerException

17

Question 17 of 30

Which exception is thrown when an array is accessed with an illegal index?

NullPointerException

ArrayIndexOutOfBoundsException

IllegalArgumentException

NumberFormatException

18

Question 18 of 30

What is the output of: System.out.println(10 + 20 + "Java" + 30 + 40);

30Java3040

1020Java3040

30Java70

10203040Java

19

Question 19 of 30

Which keyword is used to prevent method overriding in Java?

static

final

abstract

private

20

Question 20 of 30

What is the correct way to start a thread in Java?

thread.run()

thread.begin()

thread.start()

thread.execute()

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JavaPractice Questions