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Byron is a master software engineer working in the IT and Telecom domains. He is an applications developer in a wide variety of applications/services. He is currently acting as the team leader and technical architect for a proprietary service creation and integration platform for both the IT and Telecom industries in addition to a in-house big data real-time analytics solution. He is always fascinated by SOA, middleware services and mobile development. Byron is co-founder and Executive Editor at Java Code Geeks.

TreeSet size example

This is an example of how to get a TreeSet size, that is the number of elements that a TreeSet contains. Getting the TreeSet size implies that you should:

  • Create a new TreeSet.
  • Populate the set with elements, with add(E e) API method of TreeSet.
  • Invoke size() API method of TreeSet, to get the number of elements in the set.
  • To check if the size changes with an element’s removal, we can remove an element from the set, with remove(Object o) API method of TreeSet and then check its size again.

Let’s take a look at the code snippet that follows:

package com.javacodegeeks.snippets.core;

import java.util.TreeSet;
public class TreeSetSizeExample {
  public static void main(String[] args) {
    // Create a TreeSet and populate it with elements
    TreeSet treeSet = new TreeSet();
    // int size() method returns the number of elements in the TreeSet   
    System.out.println("Size of TreeSet : " + treeSet.size());
    // Remove one element from the TreeSet using remove method
    System.out.println("Size of TreeSet : " + treeSet.size());


Size of TreeSet : 3
Size of TreeSet : 2

This was an example of how to get a TreeSet size in Java.

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