VBScript Keywords
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) |
 |
|
Get Your Diploma!
W3Schools' Online Certification Program is the perfect solution for busy
professionals who need to balance work, family, and career building.
The HTML Certificate is for developers who want to document their knowledge of HTML, XHTML, and CSS.
The JavaScript Certificate is for developers who want to document their knowledge of JavaScript and the HTML DOM.
The XML Certificate is for developers who want to document their knowledge of XML, XML DOM and XSLT.
The ASP Certificate is for developers who want to document their knowledge of ASP, SQL, and ADO.
The PHP Certificate is for developers who want to document their knowledge of PHP and SQL (MySQL).
|
|
