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
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