Hello All...



What are the differences between a Class, a Procedure, and a Function?



I believe the difference between a Procedure and Function is a Procedure

does something, but doesn't return a value, where as a Function does return

a value.



Is this true? How does a class fit in?



Thanks,

Scott

Is a function not a procedure? ;)



You have functions and subprocedures.  Both are procedures.

Functions can return a value, subprocedures can't.

Methods are class procedures which can be either subprocedures or functions.

There is a special type of procedure in a class, called a property.



A class is a structure that is typically comprised of many procedures and

variables.  These can be public or private. The procedures are the classes

methods and properties.  In most cases when you make a class, you store the

class' data in private variables, then create public procedures (properties)

to access the private data. This gives you a lot of power over handling the

data contained in the private variables.



You can develop your own class (as a VBScript class or in a component), then

in an ASP page, create an instance of that class as an object. Then you can

access all the public properties and methods of that object.



Look at the ASP Response object for example:



Response.Buffer	<-- This is a Property.  It's actually a function that sets

a private (internal) variable in the class.

Response.Write	<-- This is a Method.  It's a subroutine. You know what that

does.

Response.End	<-- Another Method.



Classes can get very complex internally, which is the beauty of them. Take

the Request object for example. That contains several collections like

Cookies, Form, QueryString and ServerVariables.  All the internal workings

allow us to access the members of those collections with the simple syntax

of ...("SomeName").  When you develop your own classes, you can create

collections of other classes and use them in a similar fashion.



I'd be happy to go into more detail if you are interested, otherwise, grab

one of Wrox books.  There are several that have information on classes.

Wrox's VBScript Programmer's Reference has a decent section on creating

VBScript Classes that you put right in line with your ASP.



HTH,

Peter



-----Original Message-----

From: Scott Watermasysk [mailto:swatermasysk@C...]

Sent: Thursday, March 29, 2001 8:29 AM

To: ASP Web HowTo

Subject: [asp_web_howto] Class - Procedure - Function





Hello All...



What are the differences between a Class, a Procedure, and a Function?



I believe the difference between a Procedure and Function is a Procedure

does something, but doesn't return a value, where as a Function does return

a value.



Is this true? How does a class fit in?



Thanks,

Scott