Functional Programming in Java, 2nd Edition

Picking an Element

It’s reasonable to expect that picking one element from a collection would be simpler than picking multiple elements. But there are a few complications. Let’s look at the complexity introduced by the habitual approach and then bring in lambda expressions to solve it.

Let’s create a method that will look for an element that starts with a given letter, and print it.

collections/fpij/PickAnElement.java

public static void pickName(
  final List<String> names, final String startingLetter) {
  String foundName = null;
  for(String name : names) {
    if(name.startsWith(startingLetter)) {
      foundName = name;
      break;
    }
  }
  System.out.print(String.format("A name starting with %s: ", startingLetter));

  ...