Time/Space complexity of PHP Array

Is there a way or a resource for finding the time and space complexity of the Array implementation in PHP other than calculating it by hand?

An array in PHP is actually an ordered map. A map is a type that associates values to keys. This type is optimized for several different uses; it can be treated as an array, list (vector), hash table (an implementation of a map), dictionary, collection, stack, queue, and probably more. As array values can be other arrays, trees and multidimensional arrays are also possible. - php.net

From what I can tell it would seem that it has the general complexity of a map