How to make a field hold an array, and how to put values in there, and how to loop through an array?

[Khalil_SLEIMI]

Hi there, I'm new to the elk stack, and want some advice concerning how to manipulate json objects. long story short, I have a json that I extracted from an xml, and now, want to change the json of the output, that's why I want to do this:
I want to split some fields with respect to spaces (similar to .split(' ') in java) and then add the array into another field.
I also want to conditionally check some fields (if [id][idType] == "Gender" then [gender] = [id][idNumber] )
I don't know where to start. So please help me here
Thank you