Function Object in Java

Question

I wanna implement a javascript like method in java , is this possible ?

Say , I have a Person class :

public class Person {
 private String name ;
 priva         


        

Answer 1

Yes, this is easy in a functional programming language.. in Java it's a little more complex but you can work out something like this, using also generics types when possible:

public class TestCase {
    static interface Transformable {};

    static class Person implements Transformable {
        Person(String name, int age) {
            this.name = name;
            this.age = age;
        }

        public String name;
        public int age;
    }

    static interface Modifier {
        void modify(Transformable object);
    }

    static class AgeIncrementer implements Modifier {
        public void modify(Transformable p) {
            ++((Person)p).age;
        }
    }

    static void applyOnList(List objects, Modifier modifier) {    
        for (Transformable o : objects) {
            modifier.modify(o);
        }
    }

    public static void main(String[] args) {
        ArrayList l = new ArrayList();
        l.add(new Person("John", 10));
        l.add(new Person("Paul", 22));
        l.add(new Person("Frank", 35));

        applyOnList(l, new AgeIncrementer());

        for (Person p : l)
            System.out.println(p.age);
    }
}