Overriding and dispatch

Overriding — a subclass redefines an inherited method with the same signature:

public class Cat extends Pet {
    public Cat(String name) {
        super(name);
    }

    public String speak() {           // overrides Pet.speak
        return "meow";
    }
}

Which method runs depends on the object's class, not the variable's:

Pet p = new Cat("Mimi");
p.speak();          // "meow" — the Cat method runs
p.getName();        // works: inherited from Pet

The variable type decides what you may call; the object type decides which version executes. That sentence answers half the exam's inheritance questions.

super.method() extends rather than replaces:

public String speak() {
    return super.speak() + " purr";
}

@Override is optional but recommended — the compiler then catches misspelled signatures (an overload in disguise).

equals reminder: AP classes override equals(Object other), cast inside, and compare fields — or provide a custom equalsName-style method when the exam wants simpler code. We follow the exam's custom-method style here.