PHP中的ArrayAccess用法

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最近看laravel源码，发现里面用了很多框架类实现了ArrayAccess接口，以前对这块不是很熟悉，查了一下这个语法的用法，发现这个其实就是实现让对象以数组形式来使用。

在官方文档上：

ArrayAccess {/* Methods */abstract public boolean offsetExists ( mixed $offset )abstract public mixed offsetGet ( mixed $offset )abstract public void offsetSet ( mixed $offset , mixed $value )abstract public void offsetUnset ( mixed $offset )}

实现上面的方法，下面举个实例

<?php/** * Created by PhpStorm. * User: wangHan * Date: 2016/10/21 * Time: 14:07 */class Human implements ArrayAccess{    private $elements;    public function __construct()    {        $this->elements = [            "boy" => "male",            "girl" => "female"        ];    }    public function offsetExists($offset)    {        // TODO: Implement offsetExists() method.        return isset($this->elements[$offset]);    }    public function offsetGet($offset)    {        // TODO: Implement offsetGet() method.        return $this->elements[$offset];    }    public function offsetSet($offset, $value)    {        // TODO: Implement offsetSet() method.        $this->elements[$offset] = $value;    }    public function offsetUnset($offset)    {        // TODO: Implement offsetUnset() method.        unset($this->elements[$offset]);    }}$human = new Human();$human['people'] = "boyAndGirl"; ////自动调用offsetSetif(isset($human['people'])) {   ////自动调用offsetExists    echo $human['boy'];//自动调用offsetGet    echo '<br />';    unset($human['boy']);//自动调用offsetUnset    var_dump($human['boy']);}// // 输出结果  male   null

引申下,配合单例使用才好！可以在自己的框架中使用。如下

<?php//Configuration Classclass Configuration implements ArrayAccess {     static private $config;    private $configarray;    private function __construct() {        $this->configarray = array(            "Wang" => "Male",            "Han" => "Female"        );    }    public static function instance() {        if (self::$config == null) {            self::$config = new Configuration();        }        return self::$config;    }    function offsetExists($index) {        return isset($this->configarray[$index]);    }     function offsetGet($index) {        return $this->configarray[$index];    }     function offsetSet($index, $newvalue) {        $this->configarray[$index] = $newvalue;    }     function offsetUnset($index) {        unset($this->configarray[$index]);    }} $config = Configuration::instance();print $config["Wang"];//正如你所预料的，程序的输出是"Male"。//假如我们做下面那样的动作:$config = Configuration::instance();print $config["Han"];$config['Han'] = "Wang's Lover";// config $configTest = Configuration::instance();print $configTest ['Han']; //是的，也正如预料的，输出的将是Wang's Lover

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