GW has several data types:
Integer: Integer (ℤ)Number: Floating-point number (ℝ)String: Character string (text, messages, etc.)Boolean: Boolean (true or false)Character: Character (char), represent a letter, a number, a symbol, etc.
Note: In case of a missing value, you can use 0 for Integer and Number, "" for String, true or false for Boolean (depending on your operation), and \0 for Character.