SplDoublyLinkedList::bottom

(PHP 5 >= 5.3.0, PHP 7, PHP 8)

SplDoublyLinkedList::bottom — Peeks at the node from the beginning of the doubly linked list

说明

public SplDoublyLinkedList::bottom ( ) : mixed

参数

此函数没有参数。

返回值

The value of the first node.

错误／异常

Throws RuntimeException when the data-structure is empty.

User Contributed Notes

lincoln dot du dot j at gmail dot com 11-Jul-2017 05:30


$a = new SplDoublyLinkedList;

$arr=[1,2,3,4,5,6,7,8,9];



for($i=0;$i<count($arr);$i++){

    $a->add($i,$arr[$i]);

}



echo "SplDoublyLinkedList array last/top value " .  $a->top() ." \n";

echo "SplDoublyLinkedList array first/top value " . $a->bottom() . " \n\n";



print_r($a);



//Another Example

$spl = new SplDoublyLinkedList;



$spl->push(11);

$spl->push(2);

$spl->push(3);

$spl->push(8);

$spl->push(5);



//array last value

echo $spl->top();

echo PHP_EOL;

//Array first value

echo $spl->bottom();

echo PHP_EOL;



print_r($spl);

tstirrat at gmail dot com 27-Apr-2014 10:27


A note on top() and bottom():



Picture the doubly-linked list (or queue) in the same way that you would a stack.



Say you started with an empty queue, and added five values:



$myList = new SplDoublyLinkedList



$mylist->push(1)

$mylist->push(2)

$mylist->push(3)

$mylist->push(4)

$mylist->push(5)



$mylist->top()

-> 5



$mylist->bottom()

-> 1

rakesh dot mishra at gmail dot com 26-Jan-2011 10:39


<?php



/*

 * Examples of DoublyLinkedList

 */



$obj = new SplDoublyLinkedList();



// Check wither linked list is empty

if ($obj->isEmpty())

{

    echo "Adding nodes to Linked List<br>";

    $obj->push(2);

    $obj->push(3);

    

    echo "Adding the node at beginning of doubly linked list <br>";

    $obj->unshift(10);

}



echo "<br>Our Linked List:";

print_r($obj);



echo "<br>Pick the node from beginning of doubly linked list";

echo $obj->bottom();



?>