Excellent work! You’ve learned quite a bundle about inheritance and polymorphism in Java:

• A Java class can inherit fields and methods from another class.
• Each Java class requires its own file, but only one class in a Java package needs a main() method.
• Child classes inherit the parent constructor by default, but it’s possible to modify the constructor using super() or override it completely.
• You can use protected and final to control child class access to parent class members.
• Java’s OOP principle of polymorphism means you can use a child class object like a member of its parent class, but also give it its own traits.
• You can override parent class methods in the child class, ideally using the @Override keyword.
• It’s possible to use objects of different classes that share a parent class together in an array or ArrayList.