Java Aptitude MCQ Questions with Answers for Freshers

26. What does the hashCode() method of an object represent?

• A) A unique identifier for the object
• B) A hash value used in collections like HashMap
• C) A random value for the object
• D) The object’s memory address

27. What will be the output of the following code?

String str1 = "Hello";
String str2 = "Hello";
System.out.println(str1 == str2);

• A) true
• B) false
• C) Compilation error
• D) Runtime exception

28. Which of these operators is used for bitwise AND in Java?

• A) &&
• B) &
• C) ||
• D) ^

29. In Java, the switch statement can operate on which of these data types?

• A) int, char, byte, short, enum, String
• B) float, char, boolean, String
• C) double, long, char, String
• D) boolean, int, double, String

30. Which method is automatically called when an object is garbage collected?

• A) finalize()
• B) clean()
• C) destroy()
• D) remove()

31. What is the purpose of the super keyword in Java?

• A) To refer to the current class
• B) To refer to the parent class
• C) To create a new object
• D) To terminate the program

32. Which of the following classes is synchronized in Java?

• A) ArrayList
• B) Vector
• C) LinkedList
• D) HashMap

33. Which method in the Thread class is used to check if a thread is alive?

• A) isAlive()
• B) checkAlive()
• C) alive()
• D) threadStatus()

34. What is the correct syntax for a lambda expression in Java?

• A) (parameter) -> expression
• B) parameter -> {expression}
• C) (parameter) => expression
• D) () -> expression

35. Which exception is thrown when a thread is waiting, sleeping, or doing some other operation and is interrupted?

• A) InterruptedException
• B) IllegalStateException
• C) ArithmeticException
• D) IOException