(PHP 5 >= 5.2.0, PHP 7)
ArrayIterator::uasort — Sort with a user-defined comparison function and maintain index association
) : void
This method sorts the elements such that indices maintain their correlation with the values they are associated with, using a user-defined comparison function.
If two members compare as equal, their relative order in the sorted array is undefined.
The comparison function must return an integer less than, equal to, or greater than zero if the first argument is considered to be respectively less than, equal to, or greater than the second.
No value is returned.