Data Literal Examples

VBScript Tutorials - Herong's Tutorial Examples

∟Variant Data Type, Subtypes, and Literals

∟Data Literal Examples

This section provides a tutorial example on how to write data literals for different subtypes of Integer, Long, Double, String, Boolean, Date, Empty and Null.

Now let's write a simple VBScript code inside a HTML document to run in the host environment provided by Internet Explorer.

Run a text editor and enter the following file, data_literal.html:

<html>
<body>
<!-- data_literal.html
 - Copyright (c) 1998 HerongYang.com. All Rights Reserved.
-->
<pre>
<script language="vbscript">
   document.writeln("7=" & (7) & " : " & TypeName(7))
   document.writeln("CByte(7)=" & (CByte(7)) & " : " _ 
      & TypeName(CByte(7)))
   document.writeln("777=" & (777) & " : " & TypeName(777))
   document.writeln("777777=" & (777777) & " : " & TypeName(777777))
   document.writeln("9.99=" & (9.99) & " : " & TypeName(9.99))
   document.writeln("CSng(9.99)=" & (CSng(9.99)) & " : " _ 
      & TypeName(CSng(9.99)))
   document.writeln("0.00314159e30=" & (0.00314159e30) & " : " _ 
      & TypeName(0.00314159e30))
   document.writeln("333.333e200=" & (333.333e200) & " : " _ 
      & TypeName(333.333e200))
   document.writeln("CCur(9.99)=" & (CCur(9.99)) & " : " _ 
      & TypeName(CCur(9.99)))
   document.writeln("""Hello""=" & ("Hello") & " : " _ 
      & TypeName("Hello"))
   document.writeln("TRUE=" & (TRUE) & " : " & TypeName(TRUE))
   document.writeln("#31-Dec-1999#=" & (#31-Dec-1999#) & " : " _ 
      & TypeName(#31-Dec-1999#))
   document.writeln("Empty=" & (Empty) & " : " & TypeName(Empty))
   document.writeln("Null=" & (Null) & " : " & TypeName(Null))
</script>
</pre>
</body>
</html>

Several notes about this VBScript example:

The "writeln()" function of the "document" object is used to write text strings into the HTML document.
String concatenation operation, "&", is used to join strings together.
A special function, TypeName(), is used to show the subtype of the specified value.
The statement continuation character (_) is used to join multiple lines into a single statement.

If you open this VBScript example in IE, you will get:

7=7 : Integer
CByte(7)=7 : Byte
777=777 : Integer
777777=777777 : Long
9.99=9.99 : Double
CSng(9.99)=9.99 : Single
0.00314159e30=3.14159E+27 : Double
333.333e200=3.33333E+202 : Double
CCur(9.99)=9.99 : Currency
"Hello"=Hello : String
TRUE=True : Boolean
#31-Dec-1999#=12/31/1999 : Date
Empty= : Empty
Null= : Null

The output conforms our understanding of data literal rules described in the previous section:

"7=7 : Integer" shows that small integer numbers are not recognized as Byte values.
"CByte(7)=7 : Byte" shows that CByte() returns a Byte value.
"777777=777777 : Long" shows that large integer numbers are recognized as Long values.
"9.99=9.99 : Double" shows that small real numbers are not recognized as Single values.
"CSng(9.99)=9.99 : Single" shows that CSng() returns a Single value.
"0.00314159e30=3.14159E+27 : Double" shows that real numbers are normalized into the standard floating-point format.
"CCur(9.99)=9.99 : Currency" shows that CCur() returns a Currency value.
"TRUE=True : Boolean" shows that keywords are not case sensitive. Key word "TRUE" is the same as "True".
"#31-Dec-1999#=12/31/1999 : Date" shows that more than one date formats are supported. Both dd-MMM-yyyy and mm/dd/yyyy are valid.
"Empty= : Empty" shows that the Empty value is converted into a blank string in a string concatenation operation.
"Null= : Null" shows that the Null value is converted into a blank string in a string concatenation operation.