Introduction of VB script

VBScript Introduction

Microsoft VBScript is a general-purpose, lightweight scripting language developed by Microsoft that is inherited from Visual Basic. Nowadays, VBScript is the primary scripting language for Unified Functional Tool (UFT), which is a test automation tool.

This blog will teach you how to use VbScript scripting language for UFT scripting and general purposes.

This blog has been prepared for the beginners or intermediate to help them understand basic-to-advanced functionality of VBScript. After completing, you will find yourself at next level of understanding about VB script.

Here we are travel throughout the vbscript usage,In built functions, Methods etc.

VBScript stands for Visual Basic Scripting that forms a subset of Visual Basic for Applications (VBA).

Features of VBScript

·        VBScript is a lightweight scripting language, which has a lightning fast interpreter.

·        VBScript, for the most part, is case insensitive. It has a very simple syntax, easy to learn and to implement.

·        Unlike C++ or Java, VBScript is an object-based scripting language and NOT an Object-Oriented Programming language.

·        It uses Component Object Model (COM) in order to access the elements of the environment in which it is executing.

·        Successful execution of VBScript can happen only if it is executed in Host Environment such as Internet Explorer (IE), Internet Information Services (IIS) and Windows Scripting Host (WSH)

VbScript – Version History and Uses 

VBScript was introduced by Microsoft way back in 1996 and the first version was 1.0. The Current Stable version of VBScript is 5.8, which is available as part of IE8 or Windows 7.

The VBScript usage areas are aplenty and not restricted to the below list.

·        VBScript is used as a scripting language in one of the popular Automation testing tools – Unified Functional Tool Test Professional abbreviated as UFT.

·        Windows Scripting Host, which is used mostly by Windows System administrators for automating the Windows Desktop.

Also it has some disadvantageous mentioned as below

Disadvantages

·        VBscript is used only by IE Browsers. Other browsers such as Chrome, Firefox DONOT Support VBScript. Hence, JavaScript is preferred over VBScript.

·        VBScript has a Limited command line support.

·        Since there is no development environment available by default, debugging is difficult.

Whitespace and Line Breaks

VBScript ignores spaces, tabs and newlines that appear within VBScript programs.

Because one can use spaces, tabs and newlines freely within the program so you are free to format and indent your programs that makes the code easy to read and understand and no statement terminator like semicolon.

Single Line Syntax

Colons are used when two or more lines of VBScript ought to be written in a single line. Hence, in VBScript, Colons act as a line separator.

  var1 = 10 : var2 = 20

  var3 = var1 + var2 :  var3 = var3 + 2

Multiple Line Syntax

When a statement in VBScript is lengthy and if user wishes to break it into multiple lines, then the user has to use underscore "_".

This improves the readability of the code. The following example illustrates how to work with multiple lines.

  var1 = 10 

  var2 = 20

  var3 = var1 + var2  

Reserved Words

The following list shows the reserved words in vb Scripting. These reserved words should not be used as a constant or variable or any other identifier names.

Loop	LSet	Me
Mod	New	Next
Not	Nothing	Null
On	Option	Optional
Or	ParamArray	Preserve
Private	Public	RaiseEvent
ReDim	Rem	Resume
RSet	Select	Set
Shared	Single	Static
Stop	Sub	Then
To	True	Type
And	As	Boolean
ByRef	Byte	ByVal
Call	Case	Class
Const	Currency	Debug
Dim	Do	Double
Each	Else	ElseIf
Empty	End	EndIf
Enum	Eqv	Event
Exit	False	For
Function	Get	GoTo
If	Imp	Implements
In	Integer	Is
Let	Like	Long
TypeOf	Until	Variant
Wend	While	With
Xor	Eval	Execute
Msgbox	Erase	ExecuteGlobal
Option Explicit	Randomize	SendKeys

Case Sensitivity

VBScript is a case-insensitive language. This means that language keywords, variables, function names and any other identifiers need NOT be typed with a consistent capitalization of letters. So identifiers int_counter, INT_Counter and INT_COUNTER have the same meaning within VBScript.

VBScript in Internet Explorer

Here are simple steps to turn on or turn off VBScript in your Internet Explorer:

·        Follow Tools-> Internet Options from the menu

·        Select Security tab from the dialog box

·        Click the Custom Level button

·        Scroll down till you find Scripting option

·        Select Enable radio button under Active scripting

·        Finally click OK and come out

To disable VBScript support in your Internet Explorer, you need to select Disable radio button under Active scripting.

VBScript Variables

Variable is a named memory location used to hold a value that can be changed during the script execution. VBScript has only ONE fundamental data type,Variant.

Rules for Declaring Variables:

·        Variable Name must begin with an alphabet.

·        Variable names cannot exceed 255 characters.

·        Variables Should NOT contain a period (.)

·        Variable Names should be unique in the declared context.

Declaring Variables

Variables are declared using “dim” keyword. Since there is only ONE fundamental data type, all the declared variables are variant by default. Hence, a user NEED NOT mention the type of data during declaration.

Example 1: In this Example, IntValue can be used as a String, Integer or even arrays.

Dim Var1

Example 2: Two or more declarations are separated by comma (,)

Dim Variable1, Variable2

Assigning Values to the Variables

Values are assigned similar to an algebraic expression. The variable name on the left hand side followed by an equal to (=) symbol and then its value on the right hand side.

Rules:

·        The numeric values should be declared without double quotes.

·        The String values should be enclosed within doublequotes(")

·        Date and Time variables should be enclosed within hash symbol(#)

Examples:

Dim StrValue        

StrValue = “VBScript”

 

Scope of the Variables

Variables can be declared using the following statements that determines the scope of the variable. The scope of the variable plays a crucial role when used within a procedure or classes.

• Dim
• Public
• Private

Dim

Variables declared using “Dim” keyword at a Procedure level are available only within the same procedure. Variables declared using “Dim” Keyword at script level are available to all the procedures within the same script.

Public

Variables declared using "Public" Keyword are available to all the procedures across all the associated scripts. When declaring a variable of type "public", Dim keyword is replaced by "Public".

Example : In the below example, Var1 and Var2 are available at script level while Var3 is available across the associated scripts and procedures as it is declared as Public.

Private

Variables that are declared as "Private" have scope only within that script in which they are declared. When declaring a variable of type "Private", Dim keyword is replaced by "Private".

Declaring Constants

Constant is a named memory location used to hold a value that CANNOT be changed during the script execution. If a user tries to change a Constant Value, the Script execution ends up with an error. Constants are declared the same way the variables are declared.

[Public | Private] Const Constant_Name = Value

The Constant can be of type Public or Private. The Use of Public or Private is Optional. The Public constants are available for all the scripts and procedures while the Private Constants are available within the procedure or Class. One can assign any value such as number, String or Date to the declared Constant.

What is an operator?

Simple answer can be given using expression 4 + 5 is equal to 9. Here, 4 and 5 are called operands and + is called operator. VBScript language supports following types of operators:

Arithmetic Operators

Comparison Operators

Logical (or Relational) Operators

Concatenation Operators

The Arithmetic Operators

There are following arithmetic operators supported by VBScript language:

Assume variable A holds 5 and variable B holds 10, then:

Operator	Description
+	Adds two operands
-	Subtracts second operand from the first
*	Multiply both operands
/	Divide numerator by denumerator
%	Modulus Operator and remainder of after an integer division
^	Exponentiation Operator

 

The Comparison Operators

There are following comparison operators supported by VBScript language:

Assume variable A holds 10 and variable B holds 20, then:

Operator	Description
==	Checks if the value of two operands are equal or not, if yes then condition becomes true.
<>	Checks if the value of two operands are equal or not, if values are not equal then condition becomes true.
>	Checks if the value of left operand is greater than the value of right operand, if yes then condition becomes true.
<	Checks if the value of left operand is less than the value of right operand, if yes then condition becomes true.
>=	Checks if the value of left operand is greater than or equal to the value of right operand, if yes then condition becomes true.
<=	Checks if the value of left operand is less than or equal to the value of right operand, if yes then condition becomes true.

The Logical Operators

There are following logical operators supported by VBScript language:

Assume variable A holds 10 and variable B holds 0, then:

Operator	Description
AND	Called Logical AND operator. If both the conditions are True then Expression becomes true.
OR	Called Logical OR Operator. If any of the two conditions are True then condition becomes true.
NOT	Called Logical NOT Operator. Use to reverses the logical state of its operand. If a condition is true then Logical NOT operator will make false.
XOR	Called Logical Exclusion. It is the combination of NOT and OR Operator. If one, and only one, of the expressions evaluates to True, result is True.

hope you have enjoyed learning, happy learning !

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