Functional Programming in Java, 2nd Edition

Iterating through a List

Iterating through a list is a basic operation on a collection, but over the years it’s gone through a few significant changes. We’ll begin with the old style and evolve an example—enumerating a list of names—to the elegant style.

We can easily create a list of names with the following code:

final List<String> friends =
  Arrays.asList("Brian", "Nate", "Neal", "Raju", "Sara", "Scott");

To create an immutable list, we may use the more recently introduced function List.of() instead of Arrays.asList().

Here’s the habitual, but not so desirable, way to iterate and print each of the elements.

collections/fpij/Iteration.java

for(int i = 0; i < friends.size(); i++) {
 System.out.println(friends.get(i)); ...