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:
php
php
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:
Program 2:
string(1) "G"
<?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:
Reference: https://www.php.net/manual/en/spldoublylinkedlist.top.phpint(5)