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:
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());   ?> |
bool(true) bool(false)
Reference: http://php.net/manual/en/ds-priorityqueue.isempty.php
