Implement linked list in php

Question

How should I implement a linked list in PHP? Is there a implementation built in into PHP?

I need to do a lot of insert and delete operations, and at same time I need

Answer 1

Here is the code in php which will implement Linked List, only with the reference of head node i.e first node and then you add at first, last and delete a key, and also maintain the code of the keys in list.

data = $item;
        $this->next = null;
    }
}

/**
 * Class LinkList
 */
class LinkList
{
    public $head = null;

    private static $count = 0;

    /**
     * @return int
     */
    public function GetCount()
    {
        return self::$count;
    }

    /**
     * @param mixed $item
     */
    public function InsertAtFist($item) {
        if ($this->head == null) {
            $this->head = new Node($item);
        } else {
            $temp = new Node($item);

            $temp->next = $this->head;

            $this->head = $temp;
        }

        self::$count++;
    }

    /**
     * @param mixed $item
     */
    public function InsertAtLast($item) {
        if ($this->head == null) {
            $this->head = new Node($item);
        } else {
            /** @var Node $current */
            $current = $this->head;
            while ($current->next != null)
            {
                $current = $current->next;
            }

            $current->next = new Node($item);
        }

        self::$count++;
    }

    /**
     * Delete the node which value matched with provided key
     * @param $key
     */
    public function Delete($key)
    {
        /** @var Node $current */
        $current = $previous = $this->head;

        while($current->data != $key) {
            $previous = $current;
            $current = $current->next;
        }

        // For the first node
        if ($current == $previous) {
            $this->head = $current->next;
        }

        $previous->next = $current->next;

        self::$count--;
    }

    /**
     * Print the link list as string like 1->3-> ...
     */
    public function PrintAsList()
    {
        $items = [];
        /** @var Node $current */
        $current = $this->head;
        while($current != null) {
            array_push($items, $current->data);
            $current = $current->next;
        }

        $str = '';
        foreach($items as $item)
        {
            $str .= $item . '->';
        }

        echo $str;

        echo PHP_EOL;
    }
}

$ll = new LinkList();

$ll->InsertAtLast('KP');
$ll->InsertAtLast(45);
$ll->InsertAtFist(11);
$ll->InsertAtLast('FE');
$ll->InsertAtFist('LE');
$ll->InsertAtFist(100);
$ll->InsertAtFist(199);
$ll->InsertAtLast(500);

$ll->PrintAsList();
echo 'Total elements ' . $ll->GetCount();
echo PHP_EOL;
$ll->Delete(45);
$ll->PrintAsList();
echo 'Total elements ' . $ll->GetCount();
echo PHP_EOL;
$ll->Delete(500);
$ll->PrintAsList();
echo 'Total elements ' . $ll->GetCount();
echo PHP_EOL;
$ll->Delete(100);
$ll->PrintAsList();
echo 'Total elements ' . $ll->GetCount();
echo PHP_EOL;

Code out put as:

$ php LinkList.php
199->100->LE->11->KP->45->FE->500->
Total elements 8
199->100->LE->11->KP->FE->500->
Total elements 7
199->100->LE->11->KP->FE->
Total elements 6
199->LE->11->KP->FE->
Total elements 5