Cross Ref > Language Basics

ASP Classic is not case sensitive. My preference for all languages where case sensitivity does not matter is to use camel caps as in the first example above. Many developers coming from a case sensitive language prefer to use all lowercase.

Syntax Example:   You can use any of the following: Response.Write "Hello" response.write "Hello" RESPONSE.WRITE "Hello" REsponse.WritE "Hello"

VB Classic is not case sensitive. If you type any other case for commands or variables, VB Classicwill change it to the "accepted" or "defined" case. For example, if you type msgbox it is converted to MsgBox.

MsgBox ("hello")

In .ASP html pages, you embed ASP code between <% and %>.

ASP Classic code blocks are surrounded by statement ending keywords that all use End such as End Sub, End If, and WEnd.

<%

Sub x

End Sub

If x Then

End If

While x

WEnd

%>

VB Classic code blocks are surrounded by statement ending keywords that all use End such as End Sub, End If, and WEnd.

Sub x

End Sub

If x Then

End If

While x

WEnd

Commenting Code
ASP Classic, like all the VB-based languages, uses a single quote (') or the original class-style basic "REM" (most developers just use a quote). ASP Classic does NOT have a multiple line comment.

Preprocessor Directives - @ and #
An @ is used for preprocessor directives within ASP code (within <% %>) and a # is used for HTML-style preprocessor directives.

Note: ASP Classic does not support VB Classic's #If directive.

'Single line comment.

REM Old school single line comment.

<%@LANGUAGE=VBScript%>

<!-- #Include File="includes.inc" -->

 ASP Classic Comments (' or REM)

Commenting Code
VB Classic, like all the VB-based languages, uses a single quote (') or the original class-style basic "REM" (most developers just use a quote). VB Classic does NOT have a multiple line comment.

Directives - #

Directives are sometimes called compiler or preprocessor directives. A # is used for directives within VB Classic code. VB Classic offers only an #If..then/#ElseIf/#Else directive.

'Single line comment.
 

REM Old school single line comment.
 
#If MyDirective Then
  '...some code.
#End If

 VB Classic Comments (' or REM)

Scope can be Public or Private. Public Const is the same as just specifying Const. As with variables, all constants are variants. You do not specify the type, it's implied.

Const kPI = 3.1459

Const kName = "Mike"

//Public variable:

Public Const kFeetToMeter=3.28, kMeterToFeet=.3

 ASP Classic Constants (Const kPI = 3.1459)

Scope can be Public, Global, or Private. The use of the newer Public keyword is preferred to the older Global. Private Const is the same as just specifying Const.

Const kPI = 3.1459

Const kName = "Mike"

//Public variable:

Public Const kFeetToMeter=3.28, kMeterToFeet=.3

 VB Classic Constants (Const kPI = 3.1459)

A return marks the end of a statement and you cannot combine statements on a single line of code. You can break a single statement into two or more code lines by using a space and underscore " _".

Response.Write("Hello1")
Response.Write("Hello2")
Response.Write("Hello3")
 
'The following commented code on a single line does not work...
' Response.Write("Hello4")  Response.Write("Hello5")
 
'Two or more lines works too with a space+underscore:
Response.Write _
  ("Hello6")

A return marks the end of a statement and you cannot combine statements on a single line of code. You can break a single statement into two or more code lines by using a space and underscore " _".

MsgBox "Hello1"
MsgBox "Hello2"
MsgBox "Hello3"
 
'The following commented code 
'on a single line does not work...
'MsgBox "Hello4"  MsgBox "Hello5"
 
'Two or more lines works too with a space+underscore:
MsgBox _
 "Hello6";

String literals are quoted as in "Prestwood". If you need to embed a quote use two quotes in a row.

To specify a floating point literal between 1 and -1, you can preceed the decimal with a 0 or not (both work). In other words, preceding and following decimals are allowed (both .1 and 0.1). Trailing decimals are also allowed (1, 1., and 1.0 are all equivalent and allowed).

Response.Write "Hello"

Response.Write "Hello ""Mike""."

'Does ASP evaluate this simple

'floating point math correctly? No! 

If (.1 + .1 + .1) = .3 Then
 Response.Write "Correct"
Else
 Response.Write "Not correct"
End If

String literals are quoted as in "Prestwood". If you need to embed a quote use two quotes in a row.

To specify a floating point literal between 1 and -1, you can preceed the decimal with a 0 or not (both work). In other words, preceding and following decimals are allowed (both .1 and 0.1). Trailing decimals are optimized out and replaced with # if only integer values are used.

MsgBox ("Hello")

MsgBox ("Hello ""Mike"".")

'Does VB evaluate this simple

'floating point math correctly? No! 

If (.1 + .1 + .1) = 0.3 Then
  MsgBox "Correct"
Else
  MsgBox "Not correct"
End If

ASP Classic is a loosely typed language. No variable types in ASP (all variables are variants). Declaring variables is even optional unless you use the Option Explicit statement to force explicit declaration of all variables with Dim in that script. Using Option Explicit is strongly recommended to avoid incorrectly typing an existing variable and to avoid any confusion about variable scope.

For example, at the top of my common include file, I have the following:

<%@LANGUAGE=VBScript%>
<%
Option Explicit
'...more code here.

%>

Dim Fullname
Dim Age

Dim Weight

FullName = "Mike Prestwood"

Age = 32

Weight = 154.4

'Declaritive assignment not supported:

''Dim Married = "Y"   '>>>Not supported.

VB Classic is a loosely typed language. Declaring variables is optional unless you use the Option Explicit statement to force explicit declaration of all variables with Dim, Private, Public, or ReDim. Using Option Explicit is strongly recommended to avoid incorrectly typing an existing variable and to avoid any confusion about variable scope.

Undeclared variables are variants. To specifically declare a variant, use:

Dim x As Variant

Dim x 

Common data types include Byte (0..255), Boolean, Integer (2-byte integers), Long (4-byte integers), Currency, Single (32-bit number), Double (64-bit number), Date, String, and variant.

Variables declared with Dim at the module level are available to all procedures within the module. At the procedure level, variables are available only within the procedure.

Dim FullName As String
Dim Age As Integer
Dim Weight As Double

FullName = "Mike Prestwood"

Age = 32

Weight = 154.4

'Declaritive assignment not supported:

''Dim Married As String = "Y"   '>>>Not supported.

 VB Classic Variables (Dim x As Integer)