The following example shows how to iterate over a TreeSet using Iterator.

Different ways of iterating over a TreeSet

package com.javaguides.collections.treesetexamples; import java.util.Iterator; import java.util.SortedSet; import java.util.TreeSet; public class IterateOverTreeSetExample { public static void main(String[] args) { // Creating a TreeSet SortedSet < String > fruits = new TreeSet < > (); // Adding new elements to a TreeSet fruits.add("Banana"); fruits.add("Apple"); fruits.add("Pineapple"); fruits.add("Orange"); System.out.println("=== Iterate over a HashSet using iterator() ==="); Iterator < String > fruitIterator = fruits.iterator(); while (fruitIterator.hasNext()) { String fruit = fruitIterator.next(); System.out.println(fruit); } System.out.println("=== Iterate over a HashSet using iterator() and Java 8 forEachRemaining() method ==="); fruitIterator = fruits.iterator(); fruitIterator.forEachRemaining(fruit - > { System.out.println(fruit); }); } }

Output

=== Iterate over a HashSet using iterator() === Apple Banana Orange Pineapple === Iterate over a HashSet using iterator() and Java 8 forEachRemaining() method === Apple Banana Orange Pineapple

Reference

https://www.javaguides.net/2018/07/guide-to-treeset-class.html