AppleScript: The Definitive Guide

Name

null

Description

Like missing value, this is implemented as a class with no values, and can be used as a placeholder to signal a nonvalue. I’ve never found a use for it in communicating with a scriptable application, nor have I ever seen an application return it as a result. But I do sometimes use it in my own scripts, as a way of giving a variable or record item a value to prevent it from being undefined (and causing an error), without its having any particular value belonging to a useful class.

Example

set aPerson to {name:null, age:null, town:null}