Php 获取具有以特殊字符开头的键的关联数组

我有如下数组

Array
(
    [0] => stdClass Object
        (
            [id] => 67
            [contact_id] => 
            [status] => Complete
            [is_test_data] => 0
            [datesubmitted] => 2018-05-24 03:56:35
            [SessionID] => 1527148487_5b066fc7bdcd75.00827785
            [Language] => English
            [datestarted] => 2018-05-24 03:54:47
            [iLinkID] => 6528804
            [sResponseComment] => 
            [responseID] => 67
            [[question(9)]] => Yes
            [[question(24)]] => Satisfied
            [[question(25)]] => 
            [[question(26)]] => 
            [[question(27)]] => 
            [[question(28)]] => 
            [[question(29)]] => 
            [[question(31)]] => Likely
            [[question(32)]] => 
            [[question(33)]] => 26-35
            [[question(35)]] => Male
            [[question(36)]] => 
            [[question(37)]] => No
)
)

Array
(
    [0] => Array
        (
            [id] => 67
            [submitted] => 2018-05-24 03:56:35,
            [question_9]=>yes

        )
)

我正试着从下面的例子中推导出来

Array
(
    [0] => stdClass Object
        (
            [id] => 67
            [contact_id] => 
            [status] => Complete
            [is_test_data] => 0
            [datesubmitted] => 2018-05-24 03:56:35
            [SessionID] => 1527148487_5b066fc7bdcd75.00827785
            [Language] => English
            [datestarted] => 2018-05-24 03:54:47
            [iLinkID] => 6528804
            [sResponseComment] => 
            [responseID] => 67
            [[question(9)]] => Yes
            [[question(24)]] => Satisfied
            [[question(25)]] => 
            [[question(26)]] => 
            [[question(27)]] => 
            [[question(28)]] => 
            [[question(29)]] => 
            [[question(31)]] => Likely
            [[question(32)]] => 
            [[question(33)]] => 26-35
            [[question(35)]] => Male
            [[question(36)]] => 
            [[question(37)]] => No
)
)

Array
(
    [0] => Array
        (
            [id] => 67
            [submitted] => 2018-05-24 03:56:35,
            [question_9]=>yes

        )
)

我只是尝试了数组映射

$derived=array_map(function ($a){ return array('id'=>$a->id,
                                                'submitted'=>$a->datesubmitted,
                                                 'question_9'=>$a->[question(9)]//this is not a right way, what is best practice
                                                );

                               }, $survey_array);

error :Parse error: syntax error, unexpected '[', expecting identifier (T_STRING) or variable (T_VARIABLE) or '{' or '$' in

---

访问对象属性时，可以使用大括号包装特殊字符：

$a->{'[question(9)]'}

注意：这不是关联数组。从您的初始输出来看，$a是一个stdClass对象。

的可能重复项