从多维数组中提取值并放在逗号分隔的字符串中

Question

I have an array that looks like this

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
                        )
                )
        )
)

I need to extract the value from user_id and put it in a comma separated string.

For the above array, I would like to get:

1,5

I'm a bit confused how to loop this array with foreach and then how would I create the string? Or is there a better way?

Answer 1

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

This is assuming your array is named $users and $list is the output.