The value null
The value null is a reserved word, not a string. When used in place of an object belonging to an imported Java class, it has the same meaning as it does in the Java language.
Do not use null to signify an empty string. To signify an empty string, use a pair of single quotes ('') in the advanced macro format, or nothing at all in the basic macro format. If you use the value null in a string context (for example, by assigning it to a string variable), then the Macro Editor or the macro runtime will convert the value null to the string 'null'.