VBScript Tutorials - Herong's Tutorial Examples - v6.02, by Herong Yang
"Class" Statement - Defining Your Own Class
This section provides a tutorial example on how to create a class and instantiate a new object. The TypeName() function returns the class name of the specified object.
Basic things that you need to learn before writing any classes:
1. "Class" Statement - Declares the name of a class and defines properties and methods that comprise the class. Here is the "Class" statement structure:
Class class_name ' statements to define properties ' statements to define methods End Class
2. "New" Operator - Instantiates an object from the specified class. Here is the "New" operator syntax:
Set variable_name = New class_name
3. "Set" Statement - Assigns an object to a variable. Here is the "Set" statement syntax:
Set variable_name = object_expression
Now I am ready to show you that class is supported in the VBScript host environment provided by IE browser for client-side scripting. Here is my VBScript example that creates an empty class:
<html><body> <!-- Empty_Class.html - Copyright (c) 1998 HerongYang.com. All Rights Reserved. --> <pre><script language="vbscript"> ' Initiating an object from a class Dim oEmpty Set oEmpty = New EmptyClass ' Checking the object document.writeln("VarType(oEmpty)=vbObject: " _ & (VarType(oEmpty)=vbObject)) document.writeln("TypeName(oEmpty): " & TypeName(oEmpty)) ' Defining an empty class Class EmptyClass End Class </script></pre> </body></html>
Run this VBScript example in IE, you will get:
VarType(oEmpty)=vbObject: True TypeName(oEmpty): EmptyClass
Note that "TypeNmae()" function returns the class name of the specified object.
Table of Contents
Introduction of VBScript - Visual Basic Scripting Edition
Variant Data Type, Subtypes, and Literals
Numeric Comparison Operations and Logical Operations
String Operations - Concatenation and Comparison
Variable Declaration and Assignment Statement
Expression and Order of Operation Precedence
Statement Syntax and Statement Types
Array Data Type and Related Statements
Array References and Array Assignment Statements
Conditional Statements - "If ... Then" and "Select Case"
Loop Statements - "For", "While", and "Do"
"Function" and "Sub" Procedures
Inspecting Variables Received in Procedures
Error Handling Flag and the "Err" Object
Regular Expression Pattern Match and Replacement
scrrun.dll - Scripting Runtime DLL Library
Class, Property, Method and Related Statements
►"Class" Statement - Defining Your Own Class
"New" Operator and "Nothing" Object
"Public/Private" Variables and Dot Operator
"Property Let/Set/Get" Procedures
Object Methods - "Public" Procedures
"New", "Set", "Is", ".", "Nothing" - Object Operations
"StringBuffer" - A Class Example
IE Web Browser Supporting VBScript