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.
