Lecture 11 Objectives

KNOW:

• That to abstract over behavior in Java (pre-Java 8), one must design a class that implements a method, then use an instance of the class (a function object) as an argument to another method
• That Java 8 provides built-in functional interfaces to facilitate method abstraction
• That Java 8 provides lambda expressions to enable the passing of functionality as a method argument

BE ABLE TO:

• Define an interface to represent a predicate
• Use the interface to define a method that can be passed as a function object to another method
• Use Java's built-in Predicate<T> interface
• Use Java's built-in Function<T,R> interface
• Write a lambda expression
• Write test cases for methods that have function objects as parameters

Sample Exam Question:

Here is a method:

// produce a list of the dillos in the given list, brought back to life
LinkedList<Dillo> reviveAllDillos(LinkedList<Dillo> dilloList){
  LinkedList<Dillo> aliveDillos = new LinkedList<Dillo>();
  
  for (Dillo d:  dilloList){
    aliveDillos.add(new Dillo(d.length, true));
  }
  
  return aliveDillos;
}