VBScript Tutorials - Herong's Tutorial Examples

∟Array References and Array Assignment Statements

∟Array References Work Like Arrays

After learning that a scalar variable can be used to store the reference of an array, let's try to learn more about array reference:

• An array reference is a scalar value. This is why it can be assigned to a scalar variable.
• A scalar variable holding an array reference can be used like an array variable.
• "array_reference(i)" represents the element of index i of the referenced array.
• "ReDim Preserve array_reference(n)" resets the size of the referenced array.
• When an array reference is used as a function argument, the referenced array is passed into the function, not the reference. For example, "TypeName(array_reference)" returns Variant().

To show you how an array reference works I wrote the following example, array_reference.html:

<html>
<body>
<!-- array_reference.html
 - Copyright (c) 2015, HerongYang.com, All Rights Reserved.
-->
<pre>
<script language="vbscript">
   Dim aReference
   Dim anArray(1)

   anArray(0) = "Dog"
   anArray(1) = "Cat"

   aReference = anArray  'An array reference is assigned
   aReference(0) = "Pig" 'Accessing an element through the reference
   ReDim Preserve aReference(2)   'Re-sizing the referenced array
   aReference(2) = "Fox"

   upperLimit = UBound(aReference) 'The referenced array is passed
   
   document.writeln("TypeName(aReference): " & TypeName(aReference))
   document.writeln("UBound(aReference): " & upperLimit)
   For Each e In aReference
      document.writeln("   " & e )
   Next
</script>
</pre>
</body>
</html>

Here is the output:

TypeName(aReference): Variant()
UBound(aReference): 2
   Pig
   Cat
   Fox

The output confirms that all notes mentioned earlier in this section are true.

Table of Contents

 About This Book

 Introduction of VBScript - Visual Basic Scripting Edition

 Variant Data Type, Subtypes, and Literals

 Arithmetic Operations

 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

 Assigning an Array to a Scalar Variable

►Array References Work Like Arrays

 "Array()" Function - Returning a Scalar Reference of an Array

 Creating a Copy of an Array

 "Type mismatch" Runtime Error - Assignments to Array Variables

 Conditional Statements - "If ... Then" and "Select Case"

 Loop Statements - "For", "While", and "Do"

 "Function" and "Sub" Procedures

 Built-in Functions

 Inspecting Variables Received in Procedures

 Error Handling Flag and the "Err" Object

 Regular Expression Pattern Match and Replacement

 scrrun.dll - Scripting Runtime DLL Library

 Creating Your Own Classes

 IE Web Browser Supporting VBScript

 IIS ASP Server Supporting VBScript

 WSH (Windows Script Host)

 References

 Printable Copy - PDF Version