PHP SplDoublyLinkedList offsetExists() Function

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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)); 
  
?>  