Inheritance is a good way to share functionality between objects. When a class has a parent class, we say it inherits the fields and methods of its parent.
In Java, you use the extends keyword to define the parent of a class. For example:
1 public class Griffon extends FlyingCreature {
2 }
Another way to share functionality is called composition
. This means that an object holds a reference to another object and uses it to do things. For example, see the following Griffon and Wing classes:
1 class Griffon {
2 Wing leftWing = new Wing()
3 Wing rightWing = new Wing()
4 def fly() { ...
