1Z0-819 Java Fundamentals & Object-Oriented Programming 2

Question 1

What is the output of: `System.out.println(10 / 3);`?

Accepted Answer

3

Answer

Integer division truncates the decimal part, so 10 / 3 yields 3.

Question 2

Which keyword prevents a class from being subclassed in Java?

Accepted Answer

final

Answer

The `final` keyword on a class declaration prevents any other class from extending it.

Question 3

Given `String s = null; System.out.println(s instanceof String);`, what is printed?

Accepted Answer

false

Answer

`instanceof` always returns false when the left operand is null, without throwing an exception.

Question 4

Which access modifier makes a member visible only within its own class?

Accepted Answer

private

Answer

`private` restricts visibility strictly to the declaring class itself.

Question 5

What does the `super()` call inside a constructor do?

Accepted Answer

Invokes the superclass constructor

Answer

`super()` must be the first statement in a constructor and delegates to the matching superclass constructor.

(1Z0-819) Oracle Java SE 11 Developer Practice Test