AbstractQueue clear() method in Java with examples

The clear() method of AbstractQueue removes all of the elements from this queue. The queue will be empty after this call returns.

Syntax:

public void clear()

Parameters: This method does not accept any parameters.

Returns: The method does not returns anything.

Below programs illustrate clear() method:

Program 1:

// Java program to illustrate the
// AbstractQueue clear() method
import java.util.*;
import java.util.concurrent.LinkedBlockingQueue;

public class GFG1 {
    public static void main(String[] argv)
        throws Exception
    {
        // Creating object of AbstractQueue<Integer>
        AbstractQueue<Integer>
            AQ1 = new LinkedBlockingQueue<Integer>();

        // Populating AQ1
        AQ1.add(10);
        AQ1.add(20);
        AQ1.add(30);
        AQ1.add(40);
        AQ1.add(50);

        // print AQ
        System.out.println("AbstractQueue1 contains : " + AQ1);

        AQ1.clear();
        System.out.println("AbstractQueue1 : " + AQ1);
    }
}

Output:

AbstractQueue1 contains : [10, 20, 30, 40, 50]
AbstractQueue1 : []

Program 2:

// Java program to illustrate the
// AbstractQueue clear() method
import java.util.*;
import java.util.concurrent.LinkedBlockingQueue;

public class GFG1 {
    public static void main(String[] argv)
        throws Exception
    {
        // Creating object of AbstractQueue<String>
        AbstractQueue<String>
            AQ1 = new LinkedBlockingQueue<String>();

        // Populating AQ1
        AQ1.add("gopal");
        AQ1.add("gfg");
        AQ1.add("java");

        // print AQ
        System.out.println("AbstractQueue1 contains : " + AQ1);

        AQ1.clear();
        System.out.println("AbstractQueue1 : " + AQ1);
    }
}

Output:

AbstractQueue1 contains : [gopal, gfg, java]
AbstractQueue1 : []

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