The SplDoublyLinkedList::top() function is an inbuilt function in PHP which is used to return the value of last (top) node in a doubly-linked list.
Syntax:
mixed SplDoublyLinkedList::top( void )
Parameters: This function does not accepts any parameters.
Return Value: It returns the value of last node in a doubly linked list.
Below programs illustrate the SplDoublyLinkedList::top() 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"); $list->add(4, 'G');   // Use top() function var_dump($list->top());   ?> |
Output:
string(1) "G"
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); $list->push(5);   // Use top() function var_dump($list->top());   ?> |
Output:
int(5)
Reference: https://www.php.net/manual/en/spldoublylinkedlist.top.php
