PHP Ds\PriorityQueue isEmpty() Function

The isEmpty() Function of Ds\PriorityQueue class in PHP is used to whether a particular PriorityQueue instance is empty or not. It returns True if the PriorityQueue is empty otherwise it returns False.

Syntax:

bool isEmpty( )

Parameters: This function does not accepts any parameters.

Return Value: This function returns a boolean value based on whether this PriorityQueue is empty or not. It returns True if the PriorityQueue is empty otherwise it returns False.

Below programs illustrate the above method:

Program 1:

<?php

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

// Initially PriorityQueue is Empty
var_dump($pq->isEmpty());

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

// Check again if the PriorityQueue
// is Empty
var_dump($pq->isEmpty());

?>

Output:

bool(true)
bool(false)

Program 2:

<?php

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

// Initially PriorityQueue is Empty
var_dump($pq->isEmpty());

// Add elements to the PriorityQueue
$pq->push("Geeks", 1);
$pq->push("for", 2);
$pq->push("Geeks", 3);

// Check again if the PriorityQueue
// is Empty
var_dump($pq->isEmpty());

?>

Output:

bool(true)
bool(false)

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