PHP二维数组根据键值对获取一组数组 (不使用foreach)
```
$user = array(  
    0 => array(  
        'id'    => 1,  
        'name'  => '张三',  
        'email' => 'zhangsan@sina.com',  
    ),  
    1 => array(  
        'id'    => 2,  
        'name'  => '李四',  
        'email' => 'lisi@163.com',  
    ),  
    2 => array(  
        'id'    => 5,  
        'name'  => '王五',  
        'email' => '10000@qq.com',  
    ),  
    ......  
); 
```
比如我想获取当id=2时,该数组的全部内容,不使用foreach,在PHP 5.3版本下
```
$user = array(  
    0 => array(  
        'id'    => 1,  
        'name'  => '张三',  
        'email' => 'zhangsan@sina.com',  
    ),  
    1 => array(  
        'id'    => 2,  
        'name'  => '李四',  
        'email' => 'lisi@163.com',  
    ),  
    2 => array(  
        'id'    => 5,  
        'name'  => '王五',  
        'email' => '10000@qq.com',  
    )
);
$ids = array_column($user, 'id');
$new_user = array_combine($ids, $user);
var_dump($new_user[2]);
```