PHP SplDoublyLinkedList offsetExists() Function

The SplDoublyLinkedList::offsetExists() function is an inbuilt function in PHP which is used to check whether the given index exists or not.

Syntax:

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:

bool(true)
bool(false)

Program 2:

<?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:

bool(true)
bool(false)

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