A multidimensional array is an array containing one or more arrays. PHP supports multidimensional arrays that are two, three, four, five, or more levels deep. However, arrays more than three levels ...

Simple, fast and powerful PHP utility functions to flatten/unflatten multidimensional/JSON arrays into a one-dimensional array, preserving key names and joining them with customizable separators.

I must be losing my mind, because PHP is eating away at my sanity, what the hell am I doing wrong here? I'm obviously new to PHP and coming from a java / ...