Introduction to Logical Operations

This section provides a quick introduction of logical operations supported by VBScript: logical negation - Not, conjunction - And, disjunction - Or, exclusion - Xor, equivalence - Eqv, implication - Imp.

Logical operations are operations that:

There are 6 logical operations supported in VBScript:

To show you how logical operations work, I wrote the following script, logical_operation.html:

<!-- logical_operation.html
 - Copyright (c) 1998 All Rights Reserved.
<script language="vbscript">
   document.writeln(True And True)
   document.writeln(True Or True)
   document.writeln(Not True)
   document.writeln(True Xor True)
   document.writeln(True Eqv False)
   document.writeln(True Imp False)

Here is the output of this VBScript example script:


No surprises in the output. But logical equivalence operation and logical implication operation are not commonly used operations.

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

 Introduction to Numeric Comparison Operations

Introduction to 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

 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)


 Full Version in PDF/EPUB