Java Professional

What is the difference between `LinkedList` and `ArrayList` regarding random access performance?

Java ProfessionalEasy

Try Now

What does `instanceof` pattern matching (Java 16+) allow you to do?

Java ProfessionalEasy

Try Now

What is the result of `Math.floorDiv(-7, 2)` in Java?

Java ProfessionalEasy

Try Now

Which keyword prevents a method from being overridden?

Java ProfessionalEasy

Try Now

Which annotation marks a method as deprecated?

Java ProfessionalEasy

Try Now

What is the default capacity of an `ArrayList` when created with the no-argument constructor?

Java ProfessionalEasy

Try Now

What does `List.of(1, 2, 3)` produce in Java 9+?

Java ProfessionalEasy

Try Now

Which method of `ExecutorService` blocks until all submitted tasks complete?

Java ProfessionalEasy

Try Now

What is the purpose of the `default` keyword in an interface?

Java ProfessionalEasy

Try Now

What does `Thread.sleep(1000)` do?

Java ProfessionalEasy

Try Now

Which of the following is an unchecked exception?

Java ProfessionalEasy

Try Now

Which interface does `HashMap` implement?

Java ProfessionalEasy

Try Now

Which access modifier allows access from the same package and subclasses in different packages?

Java ProfessionalEasy

Try Now

What does `String.valueOf(null)` return?

Java ProfessionalEasy

Try Now

What is the output of `Optional.empty().orElse(“default”)`?

Java ProfessionalEasy

Try Now

Which class provides atomic operations on a single integer without using synchronized?

Java ProfessionalEasy

Try Now

What is the correct syntax for a method reference to an instance method of an arbitrary object?

Java ProfessionalEasy

Try Now

What does `Collections.unmodifiableList()` return?

Java ProfessionalEasy

Try Now