PHP array access-ArrayAccess sample analysis-PHP Tutorial-php.cn

PHP array access-ArrayAccess sample analysis

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Release： 2023-04-06 10:22:01

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This article mainly talks about array access in PHP, which has certain reference value. Interested friends can learn about it and hope it can help you.

I was not very familiar with ArrayAccess before. Now I will sort out the knowledge related to ArrayAccess. The ArrayAccess interface is an interface that provides the ability to access objects like accessing arrays.

The interface content is as follows:

ArrayAccess {
　　　　//检查一个偏移位置是否存在 
　　　　abstract public boolean offsetExists ( mixed $offset ); 
　　　　//获取一个偏移位置的值 
　　　　abstract public mixed offsetGet ( mixed $offset ); 
　　　　//设置一个偏移位置的值 
　　　　abstract public void offsetSet ( mixed $offset , mixed $value ); 
　　　　//复位一个偏移位置的值 
　　　　abstract public void offsetUnset ( mixed $offset ); 
}

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Used in the project to obtain website configuration:

<?php
namespace lib;
use mpf\core\Di;
class config implements \ArrayAccess{

//定义存储数据的数组
   protected $configs;
   public function __construct($configs){
       　　$this->configs = $configs;
       　　$configs = \lib\model\Home::getWebConfig();
       　　foreach( $configs as $config ){
           　　　　if( !isset($this->configs[$config[&#39;sc_key&#39;]]) ){
               　　　　$this->configs[$config[&#39;sc_key&#39;]] = $config[&#39;sc_content&#39;];
           　　　　}
       　　}
   }
   public function get($key){
       　　if( isset($this->configs[$key]) ){
           　　　　return $this->configs[$key];
       　　}elseif( $key == &#39;caipiao&#39;){
           　　　　$this->configs[&#39;caipiao&#39;] = \lib\model\Home::getLcs();  
           　　　　return $this->configs[$key];
       　　}elseif( $key == &#39;user_money&#39; ){
           　　　　if( isset($_SESSION[&#39;uid&#39;]) ){
               　　if( $_SESSION[&#39;utype&#39;] == 5 ){
                   　　　　$sql = &#39;select money from inner_user where uid=?&#39;;
               　　}else{
                   　　　　$sql = &#39;select money from user where uid=?&#39;;
               　　}
               　　　　$this->configs[&#39;user_money&#39;] = \mpf\core\Di::$Di->db->prepare_query($sql,[getUid()])->fetch(\PDO::FETCH_COLUMN);
               　　　　return $this->configs[&#39;user_money&#39;];
           　　}
       }
   }
   public function offsetExists($index){
       　　return isset($this->configs[$index]);
   }
   public function offsetGet($index){
       　　return $this->configs[$index];
   }
   public function offsetSet($index,$val){
       　　$this->configs[$index] = $val;
   }
   public function offsetUnset($index){
       　　unset($this->configs[$index]);
   }
}

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This can be used config object to directly access the configuration information content.

Configuration program:

We can use the configuration file to control the program through ArrayAccess.

1. Create a config directory in the project directory
2. Create corresponding configuration files, such as app.php and database.php, in the config directory. The file program is as follows

app.php

<?phpreturn [   
 &#39;name&#39; => &#39;app name&#39;,   
  &#39;version&#39; => &#39;v1.0.0&#39;
];

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database.php

<?php

return [
    &#39;mysql&#39; => [
        &#39;host&#39; => &#39;localhost&#39;,
        &#39;user&#39; => &#39;root&#39;,
        &#39;password&#39; => &#39;12345678&#39;
    ]
];

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3. Config.php implements ArrayAccess

<?php

namespace Config;

class Config implements \ArrayAccess
{
    private $config = [];

    private static $instance;

    private $path;

    private function __construct()
    {
        $this->path = __DIR__."/config/";
    }

    public static function instance()
    {
        if (!(self::$instance instanceof Config)) {
            self::$instance = new Config();
        }
        return self::$instance;
    }
    
    public function offsetExists($offset)
    {
        return isset($this->config[$offset]);
    }
    
    public function offsetGet($offset)
    {
        if (empty($this->config[$offset])) {
            $this->config[$offset] = require $this->path.$offset.".php";
        }
        return $this->config[$offset];
    }

    public function offsetSet($offset, $value)
    {
        throw new \Exception(&#39;不提供设置配置&#39;);
    }

    public function offsetUnset($offset)
    {
        throw new \Exception(&#39;不提供删除配置&#39;);
    }
}

$config = Config::instance();

//获取app.php 文件的 name
echo $config[&#39;app&#39;][&#39;name&#39;].PHP_EOL; //app name

//获取database.php文件mysql的user配置
echo $config[&#39;database&#39;][&#39;mysql&#39;][&#39;user&#39;].PHP_EOL; // root

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