PHP 的ArrayAccess接口 像数组一样来访问你的PHP对象-PHPphp技巧

interface ArrayAccess
boolean offsetExists($index)
mixed offsetGet($index)
void offsetSet($index, $newvalue)
void offsetUnset($index)

<?php
class UserToSocialSecurity implements ArrayAccess
{
private $db;//一个包含着数据库访问方法的对象
function offsetExists($name)
{
return $this->db->userExists($name);
}
function offsetGet($name)
{
return $this->db->getUserId($name);
}
function offsetSet($name, $id)
{
$this->db->setUserId($name, $id);
}
function offsetUnset($name)
{
$this->db->removeUser($name);
}
}
$userMap = new UserToSocialSecurity();
print "John's ID number is " . $userMap['John'];
?>