import java.util.*; // Import both ArrayList and Collections public class Main { public static void main(String[] args) { ArrayList<String> names = new ArrayList<>(); names.add("Liam"); names.add("Jenny"); names.add("Kasper"); names.add("Angie"); Collections.sort(names); // must be sorted first int index = Collections.binarySearch(names, "Angie"); System.out.println("Angie is at index: " + index); } }