How to convert multi-dimensional array into one-dimensional array in thinkphp?

Question

Array({code...}) I only want 1 and 22. How can it become $a=array('1','22');

滿天的星座 · Answer

php版本要大于5.5.0
$userid_array = array_column($x,'userid');


php版本要大于5.4.0
$userid_array = array_map(function($item){return $item['userid'];},$x);

再低就for循环吧

淡淡烟草味 · Answer

array_map("current", two-dimensional array);

伊谢尔伦 · Answer

Do you need to query by column? Such a query can directly find the data of a one-digit array

$use_id = Db->table('table')->where([])->column('user_id');