Learn JAVA MCQs
Prepare JAVA MCQs (Multiple choice Questions) for exam and job interviews.
Which of the following is not a valid Java identifier?
1) _myVar
2) 123abc
3) $myVar
4) myVar1
Answer : 123abc
What is the output of System.out.println(5 + "10");?
1) 510
2) 15
3) Error
4) None of the above
Answer : 510
Which of the following is not a feature of Java?
1) Object-oriented
2) Platform-independent
3) Pointers
4) Multithreading
Answer : Pointers
Which method is used to convert a string into an integer in Java?
1) parseInt()
2) toInt()
3) valueOf()
4) None of the above
Answer : parseInt()
Which keyword is used to inherit a class in Java?
1) inherit
2) extends
3) implements
4) None of the above
Answer : extends
Which of the following statements is true about Java interfaces?
1) Interfaces can have method bodies.
2) Interfaces cannot be instantiated.
3) Interfaces do not support multiple inheritance.
4) None of the above
Answer : Interfaces cannot be instantiated.
What is the default value of an object reference in Java?
1) 0
2) null
3) undefined
4) None of the above
Answer : null
Which of the following loops is a post-tested loop in Java?
1) for
2) while
3) do-while
4) None of the above
Answer : do-while
Which keyword is used to define a subclass in Java?
1) extends
2) super
3) this
4) None of the above
Answer : extends
Which of the following exceptions is thrown when a thread is waiting, sleeping, or occupied, and the thread is interrupted?
1) InterruptedException
2) NullPointerException
3) IOException
4) None of the above
Answer : InterruptedException