PHP SplDoublyLinkedList top() Function

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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()); 
  
?>  