TreeSet
Remove all elements from TreeSet example
With this example we are going to demonstrate how to remove all elements from a TreeSet. The TreeSet API provides methods for clearing a set and checking if it is empty. In short, to remove all elements from a TreeSet you should:
- Create a new TreeSet.
- Populate the set with elements, with
add(E e)
API method of TreeSet. - Invoke
clear()
, orremoveAll(Collection> c)
API methods to remove all elements from the TreeSet. - Invoke the
isEmpty()
API method of TreeSet to check if the set has any elements. It returns true if the set is empty.
Let’s take a look at the code snippet that follows:
package com.javacodegeeks.snippets.core; import java.util.TreeSet; public class RemoveAllElementsTreeSet { public static void main(String[] args) { // Create a TreeSet and populate it with elements TreeSet treeSet = new TreeSet(); treeSet.add("element_1"); treeSet.add("element_2"); treeSet.add("element_3"); // boolean isEmpty() method checks whether TreeSet contains any elements or not System.out.println("TreeSet empty : " + treeSet.isEmpty()); // Remove all element from the TreeSet using clear() or removeAll() methods treeSet.clear(); System.out.println("TreeSet empty : " + treeSet.isEmpty()); } }
Output:
TreeSet empty : false
TreeSet empty : true
This was an example of how to remove all elements from a TreeSet in Java.