PHP Ds\PriorityQueue clear() Function

The Ds\PriorityQueue::clear() Function in PHP is used to clear all of the elements from a PriorityQueue instance. This function just clears the instance without deleting it.

Syntax:

void public Ds\PriorityQueue::clear ( void )

Parameters: This function does not accepts any parameters.

Return Value: This function does not returns any value.

Below programs illustrate the Ds\PriorityQueue::clear() Function in PHP:

Program 1:

<?php

// Declare new PriorityQueue
$pq = new \Ds\PriorityQueue();

// Add elements to the PriorityQueue
$pq->push("One", 1);
$pq->push("Two", 2);
$pq->push("Three", 3);

echo "Initial PriorityQueue: \n";
// Display the PriorityQueue
print_r($pq);

// clear the PriorityQueue
$pq->clear();

echo "\nPriorityQueue after clearing:\n";
print_r($pq);

?>

Output:

Initial PriorityQueue: 
Ds\PriorityQueue Object
(
    [0] => Three
    [1] => Two
    [2] => One
)

PriorityQueue after clearing:
Ds\PriorityQueue Object
(
)

Program 2:

<?php

// Declare new PriorityQueue
$pq = new \Ds\PriorityQueue();

// Add elements to the PriorityQueue
$pq->push("Geeks", 10);
$pq->push("for", 20);
$pq->push("Geeks", 30);

echo "Initial PriorityQueue: \n";
// Display the PriorityQueue
print_r($pq);

// clear the PriorityQueue
$pq->clear();

echo "\nPriorityQueue after clearing:\n";
print_r($pq);

?>

Output:

Initial PriorityQueue: 
Ds\PriorityQueue Object
(
    [0] => Geeks
    [1] => for
    [2] => Geeks
)

PriorityQueue after clearing:
Ds\PriorityQueue Object
(
)

Reference: http://php.net/manual/en/ds-priorityqueue.clear.php