Using Java in Scripting Languages - Scripting in Java: Integrating with Groovy and JavaScript - page 204

// Get john's full name from the Person class
var johnSuperFullName = johnSuper.getFullName();

// Print Names
print("Extended full name:", johnFullName);
print("Super full name:", johnSuperFullName);

Extended full name: JOHN JACOBS
Super full name: John Jacobs

Notice that the getFullName() method of the extended Person class refers to
the variable named john that has been declared outside the function. The following
statement assigns the reference of an object that can be used to call the methods of the
superclass of the john object.

var _super_ = Java.super(john);

The overridden method calls the Person class' getFullName() method, converts the
name to uppercase, and returns it. The code get the superclass reference again, as shown:

// Get the reference of john's super
var johnSuper = Java.super(john);

Finally, the code prints the returned value from the Person class and the extended
Person class to show that you were really able to call the superclass method.

■ instead of using Java.super(obj) method to get the superclass object reference
of obj and call methods on it, you can also use obj.super$MethodName(args) syntax
to call the method of the superclass of the object named obj . For example, in the example,
you could have used john.super$getFullName() to call the getFullName() method
of the Person class on the object john .

Tip

Using Lambda Expressions
JavaScript supports anonymous functions that can be used as lambda expressions. The
following is an anonymous function that takes a number as an argument and returns its
square:

function (n) {
return n * n;
}