What is the TreeSet.clear() function in Java?
The TreeSet.clear() method is part of the TreeSet class in the java.util package.
TreeSet.clear() is used to remove all of the elements from a TreeSet.
The
clear()method only removes the elements from theTreeSet; it does not delete theTreeSetitself.
Syntax
public void clear()
Parameters
The TreeSet.clear() method does not take any parameters.
Return value
TreeSet.clear() does not return anything, and simply clears the TreeSet upon which the method is called.
Example
Let’s understand with the help of an example.
We have a TreeSet:
- [1, 8, 5, 3, 9]
When we use the TreeSet.clear() method on this TreeSet, it removes all the elements from the TreeSet, making the TreeSet empty.
So, the result of the TreeSet.clear() method is [ ].
Code
Let’s look at the code snippet below.
import java.io.*;import java.util.TreeSet;class Main{public static void main(String args[]){TreeSet<Integer> tree_set = new TreeSet<Integer>();tree_set.add(1);tree_set.add(8);tree_set.add(5);tree_set.add(3);tree_set.add(0);System.out.println("TreeSet: " + tree_set);tree_set.clear();System.out.println("TreeSet: " + tree_set);}}
Explanation
-
In lines 1 and 2, we import the required packages and classes.
-
In line 4, we create a
Mainclass. -
In line 6, we create a
mainfunction. -
In line 8, we declare a TreeSet of
Integertype. -
In lines 9 to 13, we use the
TreeSet.add()method to add the elements into theTreeSet. -
In line 14, we display the original
TreeSet. -
In line 15, we use the
TreeSet.clear()method to remove all the elements from theTreeSet. -
In line 16, we display the result with a message.
