GDNative C - How to transfer an array to Godot instead of a string

I've just gone through the official GDNative C example tutorial in the Godot documentation where the end result is to transfer a string from a C program to a GDScript program in Godot. What's the best way of passing a 2d array of integers and floats from the C plugin to GDScript? Also how would the code to pass an array/dictionary be different than passing a string?