The Null Data Type represents the absence of a Value, therefore, its only value is Null. The only action Null allows for is to check if a Value is Null.

The IF statement considers Null to be false, so it can be very quickly tested if a variable is Null or not.


Strictly speaking, Null is not a Data Type but a Value. This means that it cannot be generated in Studio.


To present a personalized message to a user, the following Airscript Expression will display "Hello {{name}}" if the name variable is not NULL, and it will display "Hello!" if the name variable is NULL (meaning the name is unknown).

IF(name, "Hello {{name}}", "Hello!")

It also works with the ISEMPTY function, as it has the sole purpose of determining whether or not a variable has a Null Value.