JuniorTheoryCommon

What does the program print?

JAVA

public class Main {
    public static void main(String[] args) {
        Animal a = new Cat();
        a.sound();
    }
}
class Animal {
    void sound() { System.out.print("..."); }
}
class Cat extends Animal {
    @Override void sound() { System.out.print("Meow"); }
}

Meow

Expecting ...: the declared type Animal only decides that sound may be called; the version that runs is picked by the object, a Cat.
Expecting ...Meow: an override replaces the parent's method; the parent's version runs only when the override calls super.sound().

What would the program print if Cat did not override sound?
Why does a.purr() not compile when Cat has a method purr?

Back to questions Open topic in roadmap →Answer it yourself — Quiz

Back to questions

JuniorTheoryCommon

What does the program print?

JAVA

public class Main {
    public static void main(String[] args) {
        Animal a = new Cat();
        a.sound();
    }
}
class Animal {
    void sound() { System.out.print("..."); }
}
class Cat extends Animal {
    @Override void sound() { System.out.print("Meow"); }
}

Meow

Expecting ...: the declared type Animal only decides that sound may be called; the version that runs is picked by the object, a Cat.
Expecting ...Meow: an override replaces the parent's method; the parent's version runs only when the override calls super.sound().

What would the program print if Cat did not override sound?
Why does a.purr() not compile when Cat has a method purr?

Back to questions Open topic in roadmap →Answer it yourself — Quiz