Calling Inherited Class Members

Question 1

What type of members can be accessed by a child class in its super class ?

Answer 1

A child class may have access to any public or protected members of its super class and if the child class is in the same package as the parent class, the child class may also have access to package-private members of its super class

Question 2

Give an example for a child class accessing its super class members (methods and protected fields and indirectly private fields) !

Answer 2

class Fish {
protected int size;
private int age;

public Fish(int age) {
    this.age = age;
}

public int getAge() {
    return age;
} }

public class Shark extends Fish {
private int numberOfFins = 8;
public Shark(int age) {
super(age);
this.size = 4;
}
public void displaySharkDetails() {
System.out.print(“Shark with age: “+getAge());
System.out.print(“ and “+size+” meters long”);
System.out.print(“ with “+numberOfFins+” fins”);
}
}

Question 3

Give a characteristic of the ‘this’ keyword in a child class !

Answer 3

You can use the this keyword in a child class to have access to parent members that are accessible as well as the child members

Question 4

Give a characteristic of the ‘super’ keyword in a child class !

Answer 4

The ‘super’ keyword can only be used to access members of the parent class that are accessible from the child class

Question 5

Give an example of how the exam may try to trick you with ‘super’ and ‘super()’ keywords !

Answer 5

the ‘super()’ keyword can only be used as the first non commented statement of a child’s constructor to call explicitly a parent’s constructor

the ‘super’ keyword can be used in a child’s class to call a parent’s member that is accessible