in_array() and multidimensional array

Question

I use in_array() to check whether a value exists in an array like below,

$a = array(\"Mac\", \"NT\", \"Irix\", \"Linux\");
if (in_array(\"Irix\"         


        

Answer 1

For Multidimensional Children: in_array('needle', array_column($arr, 'key'))

For One Dimensional Children: in_array('needle', call_user_func_array('array_merge', $arr))