The SplDoublyLinkedList::offsetExists() function is an inbuilt function in PHP which is used to check whether the given index exists or not.
Syntax:
php
php
bool SplDoublyLinkedList::offsetExists( $index )Parameters: This function accepts a single parameter $index which holds the index value to be checked. Return Value: It returns True if given index exist otherwise return False. Below programs illustrate the SplDoublyLinkedList::offsetExists() function in PHP: Program 1:
<?php
// Declare an empty SplDoublyLinkedList
$list = new \SplDoublyLinkedList;
// 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');
$list->rewind();
// Use SplDoublyLinkedList::offsetExists() function
// to check index exist or not
var_dump($list->offsetExists(2));
var_dump($list->offsetExists(10));
?>
Output:
Program 2:
bool(true) bool(false)
<?php
// Declare an empty SplDoublyLinkedList
$list = new \SplDoublyLinkedList();
// Use SplDoublyLinkedList::push() function to
// add elements to the SplDoublyLinkedList
$list->push(1);
$list->push(2);
$list->push(3);
$list->push(8);
$list->push(5);
// Use SplDoublyLinkedList::offsetExists() function
// to check index exist or not
var_dump($list->offsetExists(3));
var_dump($list->offsetExists(15));
?>
Output:
Reference: https://www.php.net/manual/en/spldoublylinkedlist.offsetexists.phpbool(true) bool(false)