Data Type "Variant()" - Array of Variant Values

VBScript Tutorials - Herong's Tutorial Examples - Version 5.20, by Dr. Herong Yang

VBScript Tutorials - Herong's Tutorial Examples

∟Data Type "Variant()" - Array of Variant Values

This section describes the array data type, Variant(). A tutorial example is provided to show how TypeName() and VarType() functions work on array values.

Earlier, we learned that VBScript supports only one data type: Variant, The above statement needs to be revised now because of arrays.

VBScript supports only one data type, Variant, for scalar values. Array is another data type supported in VBScript for non-scalar values.

A non-scalar value is a complex value that contains an internal structure to store more than a single piece of data.

An array is non-scalar value that contains an array structure to store a list of scalar values.

Since there is only one data type, Variant, for scalar values, VBScript only supports one array type: Array of Variant, or Variant()

Applying data type rules to variables, now we know:

A variable can be declared as a scalar variable using "Dim x".
A variable can be declared as an array variable using "Dim y()".
A scalar variable can be used to store a scalar value of data type, Variant.
An array variable can be used to store an array of scalar values of data type, Variant.
A scalar variable has a data type of Variant.
An array variable has a data type of Variant() - Array of Variant.

To show you the difference between a scalar variable and an array variable, I wrote the following example, array_type.html:

<html>
<body>
<!-- array_type.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("The scalar variable:")
   document.writeln("   IsArray(aScalar): " & IsArray(aScalar))
   document.writeln("   TypeName(aScalar): " & TypeName(aScalar))
   document.writeln("   (VarType(aScalar)=vbString): " _ 
      & (VarType(aScalar)=vbString))
   
   document.writeln("")
   document.writeln("The array variable:")
   document.writeln("   IsArray(anArray): " & IsArray(anArray))
   document.writeln("   TypeName(anArray): " & TypeName(anArray))
   document.writeln("   (VarType(anArray)=vbArray+vbVariant): " _ 
      & (VarType(anArray)=vbArray+vbVariant))
   document.writeln("   IsArray(anArray(0)): " & IsArray(anArray(0)))
   document.writeln("   TypeName(anArray(0)): " _ 
      & TypeName(anArray(0)))
</script>
</pre>
</body>
</html>

Here is the output:


The scalar variable:
   IsArray(aScalar): False
   TypeName(aScalar): String
   (VarType(aScalar)=vbString): True

The array variable:
   IsArray(anArray): True
   TypeName(anArray): Variant()
   (VarType(anArray)=vbArray+vbVariant): True
   IsArray(anArray(0)): False
   TypeName(anArray(0)): String

The output shows that:

For a scalar value, the "TypeName()" function returns the subtype name of the value.
For a scalar value, the "VarType()" function returns the subtype code of the value.
For an array value, the "TypeName()" function returns "Variant()".
For an array value, the "VarType()" function returns the sum of two codes: "vbArray+vbVariant".

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

What Is an Array?