我有一个multidim数组与子数组，我必须在php的主索引上只打印id.如何使用循环呢?

Question

简单数组示例。这里我只需要打印系列ID

Array
(
[0] => Array
(
[series_id] => 42
[userid] => 1
[views] => 0
[seasons] => Array
(
[0] => Array
(
[season_id] => 58
[series_id] => 42
[episodes] => Array
(
[0] => Array
(
[videoid] => 1223
)
)
)
)

如何编写php代码，以便我可以打印所需的数据?Foreach循环是合适的还是for循环?

Answer 1

如果我理解正确的话，您想获得数组顶层的所有series_id。

带for循环:

$series_ids = [];
for ($i = 0, $iMax = count($arr); $i < $iMax; $i++) {
$series_ids[] = $arr[$i]["series_id"];
}

一个较短的版本是array_column():

$series_ids = array_column($arr, "series_id");

两者都会给你print_r($series_ids):

Array
(
[0] => 42
)