Java Foundations·Practice drills 12

Drill 29: Explain each line — Inheritance and interfaces

Explain what each line of the example does.

Beginner 5 min read Lesson 292 of 300 Challenge included
What you will be able to do
  • Explain what each line of the example does.

Practice task

Explain what each line of the example does.

Lesson.javaJava
abstract class Lesson {
    private final String title;

    Lesson(String title) {
        this.title = title;
    }

    public String title() {
        return title;
    }

    public abstract int minutes();
}

interface Scored {
    int maxScore();
}

final class Quiz extends Lesson implements Scored {
    Quiz(String title) {
        super(title);
    }

    @Override
    public int minutes() {
        return 10;
    }

    @Override
    public int maxScore() {
        return 100;
    }
}

class Module {
    private final Lesson lesson;

    Module(Lesson lesson) {
        this.lesson = lesson;
    }

    public String title() {
        return lesson.title();
    }
}
Your turn

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Explain what each line of the example does.

TEXT · starter
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Lesson 292 of 300 · 0% of course