Tests the value of an expression to determine whether it is NULL.

Syntax

IsNull ( expr )

Elements

expr

Any expression except an object reference or a Variant that contains an object reference.

The IsNull function returns TRUE (-1) if expr is NULL; otherwise it returns FALSE (0).

Usage

The IsNull function checks whether a Variant contains NULL. For example:

If IsNull(LoVar) Then Print "LoVar is NULL" Else Print LoVar

Do not use the IsNull function with an object reference variable argument; to test whether an object reference variable has been initialized, use (objref Is Nothing).

Language cross-reference

Built-in constants in LotusScript language

Testing object references in LotusScript language

Example
See Also

LotusScript Language Reference: I through L
Constants
IsEmpty function
IsUnknown function

Glossary