A class to work with the idea of collections in PHP

ArrayCollection.php

<?php
	
namespace Collections;

class ArrayCollection {
    private $elements;

    public function __construct(array $_elements = array()) {
        $this->elements = $_elements;
    }

    public function set($key, $value) {
        $this->elements[$key] = $value;
    }

    public function add($value) {
        $this->elements[] = $value;

        return true;
    }
	
    public function addWithKey($key, $value) {
        if ($this->constainsKey($key)) return false;

        $this->elements[$key] = $value;

        return true;
    }

    public function clear() {
        $this->elements = array();
    }

    public function constainsKey($key) {
        return (isset($this->elements[$key]) || array_key_exists($key, $this->elements));
    }

    public function constainsElement($element) {
        return in_array($element, $this->elements, true);
    }

    public function indexOf($element) {
        return array_search($element, $this->elements, true);
    }

    public function count() {
        return count($this->elements);
    }

    public function toArray() {
        return $this->elements;
    }

    public function isEmpty() {
        return !$this->elements;
    }

    public function getFirst() {
        return reset($this->elements);
    }

    public function getLast() {
        return end($this->elements);
    }

    public function getCurrent() {
        return current($this->elements);
    }

    public function getNext() {
        return next($this->elements);
    }

    public function getPrev() {
        return prev($this->elements);
    }

    public function get($key) {
        if (isset($this->elements[$key])) {
            return $this->elements[$key];
        }

        return null;
    }

    public function getKeys() {
        return array_keys($this->elements);
    }

    public function getValues() {
        return array_values($this->elements);
    }

    public function removeByKey($key) {
        if (isset($this->elements[$key]) || array_key_exists($key, $this->elements)) {
            $removed = $this->elements[$key];

            unset($this->elements[$key]);

            return $removed;
        }

        return null;
    }

    public function removeByElement($element) {
        $key = array_search($element, $this->elements, true);

        if ($key !== false) {
            unset($this->elements[$key]);

            return true;
        }

        return false;
    }
}

?>