Java Flashcards

Which of the following is NOT a Java access modifier?

• public

• private

• internal

• protected

What is the default value of a boolean variable in Java if it’s an instance variable?

• true

• false

• null

• 0

Which keyword is used to prevent a class from being inherited?

• static

• final

• abstract

• private

What is the size of a Java char?

• 1 byte

• 2 bytes

• 4 bytes

• Depends on OS

Which of these exceptions is unchecked in Java?

• IOException

• SQLException

• NullPointerException

• FileNotFoundException

Which collection class maintains insertion order in Java?

• HashMap

• HashSet

• LinkedHashMap

• TreeMap

What will happen if you try to inherit from a final class?

• Compile-time error

• Runtime error

• The subclass will override it

• It will work normally

Which of the following is true about interfaces in Java?

• They can have constructors

• They can have static methods

• They can hold instance variables

• They cannot be implemented by multiple classes

Which package contains the Collection interface?

• java.io

• java.lang

• java.util

• java.sql

What is the output of System.out.println(9/2); in Java?

• 4.5

• 4

• 5

• 4.0