ASP
Variables - VBScript
ASP is not a language in
itself. To program ASP you
actually need to know the VBScript
scripting language. This means
that all VBScript variable rules
can be applied to your ASP code.
This lesson will teach you the
basics of Variables in ASP and
some good programming conventions.
Declaring a Variable in ASP
It is a good programming
practice to declare all your
variables before you use them,
even though it is not required.
Nearly all programming languages
require you to declare variables
and doing so also increases your
program's readability.
In ASP you declare a variable
with the use of the Dim keyword,
which is short for Dimension.
Dimension in english refers to the
amount of space something takes up
in the real world, but in computer
terms it refers to space in
computer memory.
Variables can be declared one
at a time or all at once. Below is
an example of both methods.
ASP Code:
<%
'Single Variable Declarations
Dim myVar1
Dim myVar2
'Multiple Variable
Declarations
Dim myVar6, myVar7, myVar8
%> |
ASP Variable Naming
Conventions
Once again, ASP uses VBScript
by default and so it also uses
VBScripts variable naming
conventions. These rules are:
- Variable name must start
with an alphabetic character (A
through Z or a through z)
- Variables cannot contain a
period
- Variables cannot be longer
than 255 characters (don't think
that'll be a problem!)
- Variables must be unique in
the scope in which it is
declared (Basically, don't
declare the same variable name
in one script and you will be
OK).
ASP - Assigning Values to ASP
Variables
Assigning values in ASP is
straightforward enough, just use
the equals "=" operator. Below we
have set a variable equal to a
number and a separate variable
equal to a string.
ASP Code:
<%
'Single Variable Declarations
Dim myString, myNum, myGarbage
myNum = 25
myString = "Hello"
myGarbage = 99
myGarbage = "I changed my
variable"
Response.Write("myNum = " &
myNum & "<br />")
Response.Write("myString = " &
myString & "<br />")
Response.Write("myGarbage = "
& myGarbage & "<br />")
%> |
Display:
myNum = 25 myString = Hello
myGarbage = I changed my
variable |
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