VB ScriptVB ScriptBy:Ali Imran Khanaliimranpk@gmail.com

• VBScript is a scripting language

•Scripting language is a lightweight programming language

•VBScript is a light version of Microsoft's programming language Visual Basic

•VBScript can be used for both client-side and server-side programming.

VBScript VariablesVBScript VariablesA variable is a "container" for information you want to store.

Naming Rules: Must begin with an alphabetic character Cannot contain a period Cannot exceed 255 characters Must be unique within its scope

Lifetime OF VariablesLifetime OF VariablesLocal Variables:

When you declare a variable within a procedure, the variable can only be accessed within that procedure. When the procedure exits, the variable is destroyed. You can have local variables with the same name in different procedures, because each is recognized only by the procedure in which it is declared.

Global Variables:If you declare a variable outside a procedure, all the procedures

on your page can access it. The lifetime of these variables starts when they are declared, and ends when the script is closed.

Variable (Cont)Variable (Cont)Declaration:

Dim Keyword is used to Declare a variableYou can Assign a Value to variable directly (without

declaring a variable). But not a good practice.Option Explicit Keyword is used to restrict

variables to be declared before their usage.Example:

Option explicitDim var_ xvar_x=1

ConstantsConstantsConst keyword is used to declare constants.It is necessary to initialize the Constant

during its declaration. You cannot change the value of constants in

later script.

Syntax:const x=1

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ArraysArrays

An array is a set of variables conveniently packages for easy handling

Sometimes you want to assign more than one value to a single variable. Then you can create a variable that can contain a series of values. This is called an array variable

Arrays (cont.)Arrays (cont.)The declaration of an array variable uses

parentheses ( ) following the variable name.

Example:

dim names(2)

names(0)=“Ali“names(1)=“Imran“names(2)=“Khan"

Arrays (cont.)Arrays (cont.)

An array can be multi dimensional.

There can be 60 (maximum) dimensions in an array.

Multiple dimensions are declared by separating the numbers in the parentheses with commas.

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ProceduresProceduresA Sub procedure:is a series of statements, enclosed by the Sub

and End Sub statements can perform actions, but does not return a

value can take arguments that are passed to it by a

calling procedure without arguments, must include an empty

set of parentheses ()

Procedures (Cont)Procedures (Cont)Sub Keyword is Used to declare a procedure.End Sub Keyword is Used to defining the

ending boundary of a procedure.Call Keyword is Used in order to invoke a

procedure.

Syntax:Sub mysub()

some statements End Sub

Call mysub()

Procedures (Cont)Procedures (Cont)Procedure can take arguments that are

passed to it by calling that procedure .

Syntax:Sub procedure name(arg1,arg2)

some statements End Sub

Call mysub(value1,value2)

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FunctionsFunctionsA Function procedure:is a series of statements, enclosed by the

Function and End Function statements can perform actions and can return a value can take arguments that are passed to it by a

calling procedure without arguments, must include an empty

set of parentheses () returns a value by assigning a value to its

name

Functions (Cont)Functions (Cont)Function Keyword is Used to declare a Function.End Function Keyword is Used to defining the

ending boundary of a Function.<Function Name> is Used in order to invoke a

Function.

Syntax:Function myfunc()

some statements End Function

myfunc

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If ConditionIf ConditionIf keyword is used for executing a set of code

when certain condition is true.Endif keyword is used to end the if condition code

block.

Syntax:

If <condition> then Some statements

End if

If-Else ConditionIf-Else Conditionif...then...else - use this keyword if you want

to select one of two sets of lines to execute

if...then...elseif - use this keyword if you want to select one of many sets of lines to execute

If-Else Condition (cont.)If-Else Condition (cont.)Syntax :

if <condition> then Some statements

ElseSome statements

end If

If-Elseif Condition (cont.)If-Elseif Condition (cont.)Syntax :

if <condition> then Some statements

Elseif <condition> thenSome statements

ElseSome statements

end If

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Select Case ConditionSelect Case ConditionSelect case keyword is used to execute one of many blocks

of code.

Syntaxselect case <variable>

case <first expected value>Some statements

case <second expected value>Some statements………………case Else

Some Statementsend select

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For LoopFor LoopFor loop is used to execute set of statements ,

pre defined number of iterations.For … Next keywords are used to implement

the For Loop.

Syntax:For <Loop initialization state> to <ending condition>

Some Statements

Next

For Loop (cont.)For Loop (cont.)Step keyword is used to increase or decrease

the counter variable by the specified value.

Syntax

For <Loop initialization state> To <ending condition> Step <Increment/Decrement value>

some statementsNext

For Loop (cont.)For Loop (cont.)You can use for loop in order to repeat a block

of code for each item in a collection, or for each element of an array.

Syntax:For Each <variable name > in <array Variable

Name> <Some Statements>Next

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Do-while loopDo-while loopDo-while keywords are used to execute

specified code for a set of times (until a condition remains true or a condition becomes false).

Syntax

Do While <Condition for loop>Some Statements

Loop

Do-while loop (cont.)Do-while loop (cont.)

Do-While can also used in following syntax:

Do some Statements

Loop While i>10

Do-Until Loop Do-Until Loop Do – Until keyword is used for repeating

some set of statements until a certain condition is true.

Syntax:Do Until <Condition>

some statmemts

Loop

Do-Until Loop (cont.)Do-Until Loop (cont.)Do-Until can also used in following syntax:

Do some statements

Loop Until <Condition>

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Built in FunctionsBuilt in FunctionsVB Script provides several built in functions

that can be used just by calling them.

Few Examples:

DateTimeInt

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Thank You !Thank You !