Variables in ASP
Declaring variables in ASP is simple, especially since all variables are
of type Variant. You don't have to declare if your variable is an
integer, string, or object. You just declare it, and it has the potential
to be anything. Here is some code creating and assigning values to a few
values:
<%@ LANGUAGE="VBSCRIPT" %>
<%
'Declare a variable. A single tick denotes
'a comment in VBScript
Dim MyName
'To declare a variable, you just put the word
'Dim in front of the variable name.
'Let's assign something to MyName
MyName = "Scott Mitchell"
'Let's create some more variables
Dim Age, Pi
Age = 20
Pi = 3.14159
'Since all variables are variants, we can
'Reassign values. (Bad coding, though!)
MyName = 45
Pi = Age
Age = "Yellow Schoolbus!"
%>
If you wanted to print out the variables, you could simply do a
Response.Write. Here is an example:
<%@ LANGUAGE="VBSCRIPT" %>
<%
'Declare a variable. A single tick denotes
'a comment in VBScript
Dim MyName
MyName = "Scott Mitchell"
'Print out MyName
Response.Write(MyName)
'To concatonate strings in VBScript, use the
'amperstand
Response.Write("My name is " & MyName)
%>
Since variables are Variable, you may be wondering how you can tell what,
exactly, is in them. There are some built-in functions which help you in
this task.
<%@ LANGUAGE="VBSCRIPT" %>
<%
'Declare the variable MyName.
Dim MyName
MyName = "Scott Mitchell"
'Will print out false
Response.Write(IsNumeric(MyName))
'Will print out false
Response.Write(IsDate(MyName))
%>
You can explicitly cast the type of a variable when you assign to it. It
is good programming technique to do that! That is because if you have
a variable SomeString with the value "5" in it, and you want to assign
it to a variable SomeInt, you don't want SomeInt to be a string but an
integer. So you could type: SomeInt = CInt(SomeString).
Here is an example:
<%@ LANGUAGE="VBSCRIPT" %>
<%
'Declare the variable MyName.
Dim MyName
'Explicitly make Myname a string
MyName = CStr("Scott Mitchell")
Dim Age, Pi
'Explicitly make MyAge an integer
Age = CInt(20)
'Explicitly make Pi a double (a floating point
'value with double preceision)
Pi = CDbl(3.14159)
%>
