EMPTY( )
Returns true if a specified expression is empty.
Syntax
EMPTY(<exp>)
<exp>
An expression of any type.
Description
Use EMPTY( ) to determine if an expression is empty. The definition of empty depends on the type of the expression:
|
Expression type |
Empty if value is |
|
Numeric |
0 (zero) |
|
String |
empty string ("") or a string of just spaces (" ") |
|
Date |
blank date ({ / / }) |
|
Logical |
false |
|
Null |
null is always considered empty |
|
Object reference |
Reference points to object that has been released |
Note that event properties that have not been assigned handlers have a value of null, and are therefore considered empty. In contrast, an object reference pointing to an object that has been released is not null; you must use EMPTY( ).
EMPTY( ) is similar to ISBLANK( ). However, ISBLANK( ) is intended to test field values; it differentiates between zero and blank values in numeric fields, while EMPTY( ) does not. EMPTY( ) understands null values and object references, while ISBLANK( ) does not. For more information, see ISBLANK( ).