Polymorphism

AP Computer Science A· difficulty 3/5

public class Animal {
    public String toString() { return "Animal"; }
}
public class Dog extends Animal {
    public String toString() { return "Dog"; }
}
// Usage:
Object o = new Dog();
System.out.print(o.toString());

What is printed?

A
$Compile error$
B
$Dog$
check_circle
C
$Animal$
D
$Object hashcode$

Explanation

toString is defined in Object and overridden by Dog. Dynamic dispatch picks Dog's version regardless of declared type.

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