从多维数组中提取值并放在逗号分隔的字符串中

Question

我有一个看起来像这样的数组

Array
(
    [1] => Array
        (
            [name] => Zeze
            [city] => Denver, 
            [state] => Colorado, 
            [country] => United States
            [user_id] => 1
            [cars] => Array
                (
                    [140] => Array
                        (
                            [cars_name] => BMW
                        )

                    [162] => Array
                        (
                            [cars_name] => Mazda
                        )
                )
        )

    [8] => Array
        (
            [name] => Lex
            [city] => Schwelm, 
            [state] => North Rhine-Westphalia, 
            [country] => Germany
            [user_id] => 5
            [cars] => Array
                (
                    [140] => Array
                        (
                            [cars_name] => Mercedes
                        )

                    [162] => Array
                        (
                            [cars_name] => Audi
                        )
                )
        )
)

我需要从中提取值user_id并将其放在逗号分隔的字符串中.

对于上面的数组,我想得到:

1,5

我有点困惑如何循环这个数组,foreach然后我将如何创建字符串？或者,还有更好的方法？

Answer 1

$uids = Array();
foreach($users as $u) $uids[] = $u['user_id'];
$list = implode(",",$uids);

这假设您的数组已命名$users并且$list是输出.