Question

Java

public class Point {

     protected int x;

     protected int y;

     public Point (int x, int y) {

          this.x = x;

          this.y = y;

     }

     public int getX() {

          return x;

     }

     public int getY() {

          return y;

     }

}

THE FOLLOWING 3 QUESTIONS REFER TO THE CODE FRAGMENT ABOVE    

1. Based on the code above, the Point Class is immutable:

• (a) TRUE
• (b) FALSE

Explain: ___________________________________________

2. Subclasses of Point have direct access to the “x” and “y” data members:

• (a) TRUE
• (b) FALSE

Explain: ___________________________________________

3. The Point Class is a subclass of the Object Class, and it does NOT implement any Interfaces:

• (a) TRUE
• (b) FALSE
  

Answer 1

1. Answer: False

Point class is not immutable because the class is not declared as final. Data members must be declared as final.

2. Answer: True

Subclasses of Point class have direct access to the X and Y because X and Y are declared as protected data members. Protected data members are accessible inside a package or sub classes in different packages.

3. Answer: True

Every class in java is a subclass of an object class. Point class is also a subclass of the Object class and it does not implement any interfaces.