Programming Groovy 2

3.6 Multimethods

Dynamic typing and dynamic languages change how objects respond to method calls.

Groovy supports polymorphism, like Java does, but it goes far beyond simply dispatching methods based on the target object’s type. Let’s look at polymorphism in Java:

// Java code
public class Employee {
  public void raise(Number amount) {
    System.out.println("Employee got raise");
  }
}

The ​Employee​ class’s ​raise​ method simply reports that it was called. Now look at the ​Executive​ class:

// Java code
public class Executive extends Employee {
  public void raise(Number amount) {
    System.out.println("Executive got raise");
  }

  public  ...