Question

I am trying to learn about the ScriptProperties object in GAS.

I tried setting a property to a value of null, and I get an error.

I can understand if like JavaScript, setting a value of null undefines
that property.

But why are you disallowing this value?
It seems reasonable (to me) to allow a script to undefine a script (or user) property.

Another question about ScriptProperties (and I assume the same holds for UserProperties),
Why when I display the value of an undefined property it displays as “undefined”,
but when I try to test for the value “undefined” (without quotes) it does not match?

It seems, that if you are going to introduce a new special attribute value of “undefined”, it should be consistent through out the system. If by “undefined” you mean null, well then
why not display it with the word “null”?

I am just trying to learn about this new environment.
All help is appreciated. Thanks for your support.

Answer 1

There is an open feature request to add support for removing properties, which you can star for updates.

The value “undefined” is not a string but rather a special value built in to JavaScript. You can refer to it like “null”:

if (foo == undefined) { ...

More information is available on the w3schools page.