PHP | SplDoublyLinkedList isEmpty() Function

The SplDoublyLinkedList::isEmpty() function is an inbuilt function in PHP which is used to check whether the doubly linked list is empty or not.

Syntax:

bool SplDoublyLinkedList::isEmpty( void )

Parameters: This function does not accepts any parameters.

Return Value: This function returns True if doubly linked list is empty, False otherwise.

Below programs illustrate the SplDoublyLinkedList::isEmpty() function in PHP:

Program 1:

<?php

// Declare an empty SplDoublyLinkedList
$list = new \SplDoublyLinkedList;

// Use isEmpty function
$res = $list->isEmpty();

var_dump($res);

// Use SplDoublyLinkedList::push() function to
// add elements to the SplDoublyLinkedList
$list->push(1);
$list->push(2);
$list->push(3);
$list->push(8);
$list->push(5);

// Use isEmpty function
$res = $list->isEmpty();

var_dump($res);

?>

Output:

bool(true)
bool(false)

Program 2:

<?php

// Declare an empty SplDoublyLinkedList
$list = new \SplDoublyLinkedList;

// Use isEmpty function
$res = $list->isEmpty();

var_dump($res);

// Use SplDoublyLinkedList::add() function to
// add elements to the SplDoublyLinkedList
$list->add(0, 30);
$list->add(1, 20);
$list->add(2, 30);
$list->add(3, "Geeks");
$list->add(4, 'G');

// Use isEmpty function
$res = $list->isEmpty();

var_dump($res);

?>

Output:

bool(true)
bool(false)

Reference: https://www.php.net/manual/en/spldoublylinkedlist.isempty.php