Assigning an Array to a Scalar Variable

This section provides a tutorial example on how to assign an array to a scalar variable. Actually, a copy of the original array is created and the reference of the copy if assigned the scalar variable.

What will happen, if you try to assign an array to a scalar variable with an assignment statement?

Read the following VBScript code example and guess what will happen:

   Dim aScalar, anArray(1)
   aScalar = anArray

VBScript has several surprise for us:

To show you how an array can be assigned to a scalar variable, I wrote the following example, array_assignment.html:

<html>
<body>
<!-- array_assignment.html
 - Copyright (c) 2015, HerongYang.com, All Rights Reserved.
-->
<pre>
<script language="vbscript">
   Dim aScalar
   Dim anArray(1)
   
   aScalar = "Rabbit"
   anArray(0) = "Dog"
   anArray(1) = "Cat"

   document.writeln()
   document.writeln("Before the assignment and changes:")
   document.writeln("   TypeName(aScalar): " & TypeName(aScalar))
   document.writeln("   TypeName(anArray): " & TypeName(anArray))

   aScalar = anArray  'A new dynamic-size array is created
                      'The reference of the new array is in aScalar

   aScalar(0) = "Pig" 'Array reference works like an array

   ReDim Preserve aScalar(2)   'The referenced array is re-sized
   aScalar(2) = "Fox"

   document.writeln()
   document.writeln("After the assignment and changes:")
   document.writeln("   TypeName(aScalar): " & TypeName(aScalar))
   document.writeln("   TypeName(anArray): " & TypeName(anArray))
   document.writeln("   aScalar(0): " & aScalar(0))
   document.writeln("   aScalar(1): " & aScalar(1))
   document.writeln("   aScalar(2): " & aScalar(2))
   document.writeln("   anArray(0): " & anArray(0))
   document.writeln("   anArray(1): " & anArray(1))
</script>
</pre>
</body>
</html>

Here is the output:

Before the assignment and changes:
   TypeName(aScalar): String
   TypeName(anArray): Variant()

After the assignment and changes:
   TypeName(aScalar): Variant()
   TypeName(anArray): Variant()
   aScalar(0): Pig
   aScalar(1): Cat
   aScalar(2): Fox
   anArray(0): Dog
   anArray(1): Cat

The output shows that:

Note that in some other languages like Java, assigning an array to a new variable creates a new reference to the original array. No new array will be created.

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

 PDF Printing Version