ConcurrentSkipListSet clear() method in Java

The java.util.concurrent.ConcurrentSkipListSet.clear() method is an in-built function in Java which removes all the elements from this set.

Syntax:

 ConcurrentSkipListSet.clear()

Parameters: The function does not accept any parameter.

Return Value: The function does not return anything.

Below programs illustrate the ConcurrentSkipListSet.clear() method:

Program 1:

/* Java Program Demonstrate clear()
method of ConcurrentSkipListSet() */
import java.util.concurrent.*;
class ConcurrentSkipListSetClearExample1 {
    public static void main(String[] args)
    {
        // Creating a set object
        ConcurrentSkipListSet<Integer> Lset =
                   new ConcurrentSkipListSet<Integer>();

        // Adding elements to this set
        for (int i = 10; i <= 50; i += 10)
            Lset.add(i);

        // Printing elements of the set
        System.out.println("The set contains: " + Lset);

        // Clear the set
        Lset.clear();

        // Printing elements of the set after clear operation
        System.out.println("After clear operation the set contains: "
                                                             + Lset);
    }
}

Output:

The set contains: [10, 20, 30, 40, 50]
After clear operation the set contains: []

Program 2:

/* Java Program Demonstrate clear()
method of ConcurrentSkipListSet() */
import java.util.concurrent.*;
class ConcurrentSkipListSetClearExample2 {
    public static void main(String[] args)
    {
        // Creating a set object
        ConcurrentSkipListSet<String> Lset =
                    new ConcurrentSkipListSet<String>();

        // Adding elements to this set
        Lset.add("alex");
        Lset.add("bob");
        Lset.add("chuck");
        Lset.add("drake");
        Lset.add("eric");

        // Printing elements of the set
        System.out.println("The set contains: " + Lset);

        // Clear the set
        Lset.clear();

        // Printing elements of the set after clear operation
        System.out.println("After clear operation the set contains: "
                                                              + Lset);
    }
}

Output:

The set contains: [alex, bob, chuck, drake, eric]
After clear operation the set contains: []

Reference: https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/ConcurrentSkipListSet.html#clear–