无需循环即可转换多维JSON数组（PHP）

Question

I'm working with a REST API and the response is given back in JSON. Here's a print_r version of what it looks like:

        [topics] => Array
            (
                [0] => stdClass Object
                    (
                        [provider] => klout
                        [value] => Facebook
                    )

                [1] => stdClass Object
                    (
                        [provider] => klout
                        [value] => Business
                    )
                [2] => stdClass Object
                    (
                        [provider] => klout
                        [value] => LinkedIn
                    )

I need to take the [provider] value and convert it into a string.

I'm running PHP 5.4 so I array_column is not an option.

I've tried the instructions from here:

$topics_array = $json->digitalFootprint->topics;
$arr = array_map(function($topics_array){ return $topics_array['value']; }, $arr);
$implode_topics = implode("[,,]", $arr);

But am returned with an error mentioning "Cannot use object of type stdClass as array"

Any help would be greatly appreciated.

Answer 1

这只是访问属性的方式的问题-它是一个对象，而不是数组：

$arr = array_map(function($topics_array){ return $topics_array->value; }, $arr);

Answer 2

try using array_map with null function in a nested foreach cycles, then colecting the values on a temporal array, and finally imploding this array. ex:

$arr = array_map(null,$topics_array);
$arr_temp = [];
foreach(array_map(null,$arr) as $i) {
    foreach(array_map(null,$i) as $j) {
      $arr_temp[] = ($j->value);
    }
}

$result_string = implode(', ', $arr_temp);