Java - Overriding - miert nem mukodik ez a kod?

Example

class Animal {

public void move() {

System.out.println("Animals can move");

}

}

class Dog extends Animal {

public void move() {

System.out.println("Dogs can walk and run");

}

public void bark() {

System.out.println("Dogs can bark");

}

}

public class TestDog {

public static void main(String args[]) {

Animal a = new Animal(); // Animal reference and object

Animal b = new Dog(); // Animal reference but Dog object

a.move(); // runs the method in Animal class

b.move(); // runs the method in Dog class

b.bark();

}

}

es a a hiba:

Output

TestDog.java:26: error: cannot find symbol

b.bark();

^

symbol: method bark()

location: variable b of type Animal

1 error

forras:

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