VBScript Keywords Keyword Description empty Used to indicate an uninitialized variable value. A variabl...
VBScript Keywords
| Keyword | Description |
|---|---|
| empty |
Used to indicate an uninitialized variable value. A
variable value is uninitialized when it is first created and no value is
assigned to it, or when a variable value is explicitly set to empty. Example: dim x 'the variable x is uninitialized! x="ff" 'the variable x is NOT uninitialized anymore x=empty 'the variable x is uninitialized! Note: This is not the same as Null!! |
| isEmpty | Used to test if a variable is uninitialized. Example: If (isEmpty(x)) 'is x uninitialized? |
| nothing | Used to indicate an uninitialized object value, or to disassociate an object variable from an object to release system resources.Example: set myObject=nothing |
| is nothing | Used to test if a value is an initialized object.
Example: If (myObject Is Nothing) 'is it unset? Note: If you compare a value to Nothing, you will not get the right result! Example: If (myObject = Nothing) 'always false! |
| null | Used to indicate that a variable contains no valid data.
One way to think of Null is that someone has explicitly set the value to
"invalid", unlike Empty where the value is "not set". Note: This is not the same as Empty or Nothing!! Example: x=Null 'x contains no valid data |
| isNull | Used to test if a value contains invalid data. Example: if (isNull(x)) 'is x invalid? |
| true | Used to indicate a Boolean condition that is correct (true has a value of -1) |
| false | Used to indicate a Boolean condition that is not correct (false has a value of 0) |
