The nullOrEmpty(...) function has just one variation, not counting syntax variations. It is used to test if a String value contains any information.  Specifically, nullOrEmpty(...) results in true if the value of the String is null, is the empty string or contains only whitespace characters (space, carriage return, newline, tab and other control characters).  If the String value contains any non-whitespace characters, then the result will be false.

Syntax:
nullOrEmpty( string-value )
string-value.nullOrEmpty()

 

Parameter	Description
string-value	The String value to be tested.