Saving array of numbers to a file

hey all. Its been a while but again looking for a hint.
I need to write an array of numbers to a file and later read them back. I was trying write and read file node but it writes and reads as a string. I need to be able to read the info back in as the original array. What am I missing?

Write it as comma separated and read it as a string and split.

I just tried the json node and it seems to work. Convert to json from array and read it back then convert back. Thanks Hellis81. You gave me the idea