W3School TIY Editor

class Main { public static void main(String[] args) { Animal myAnimal = new Animal(); Animal myPig = new Pig(); Animal myDog = new Dog(); myAnimal.animalSound(); myPig.animalSound(); myDog.animalSound(); } } class Animal { public void animalSound() { System.out.println("动物会发出声音"); } } class Pig extends Animal { public void animalSound() { System.out.println("猪的叫声：哼哼"); } } class Dog extends Animal { public void animalSound() { System.out.println("狗的叫声：汪汪"); } }