VB Script Overview

VB Script Overview

2. What is VBScript?
VBScript Basics
Data types
Variables
Constants
Conditional constructs
Iterative constructs
Arrays
User defined Procedures
Functions and subroutines
Integration of different interfaces
Session Wrap-Up
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VBScript Overview

3. VBScript is a subset of Visual Basic 4.0 language.
Developed by Microsoft to provide more processing
power to Web pages.
Used to write both server side and client side scripting.
Supports Internet Explorer and IIS (Internet Information
Service).
Is a fast, portable and lightweight scripting language.
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VBScript Overview

4. VBScript has its own collection of
Data types
Constants
Iterative constructs
Conditional constructs
Procedures
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VBScript Overview

5. VBScript supports only one data type called ‘Variant’.
The variant data type is a special kind of data type that can
contain different kinds of information.
It is the default data type returned by all functions in
VBScript.
A variant behaves as a number when it is used in a numeric
context and as a string when used in a string context.
Subtypes of data that a variant can contain:
Empty , Boolean, Integer, Long, Single, Byte, Double, Date Time,
string, Object, Error.
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VBScript Overview

6. Sub-Type Value
Empty When the variable is not initialized
Boolean Either true or false
Integer In the range of -32768 to 32767
Long In the range of -2147483648 to 2147483647
Single Single precision, floating point number in the range -3.402823E38 to
-1.401298E-45 for negative values; 1.401298E-45 to 3.402823E38 for
positive values.
Byte In the range of 0 to 255
Double Double precision, floating point number in the range -1.79769313486232E308 to
-4.94065645841247E-324 for negative values; 4.94065645841247E-324 to
1.79769313486232E308 for positive values.
DateTime Represents a date between Jan 1, 1100 to Dec, 31 9999
String Variable length string that can be up to approximately 2 billion characters in
length
Object An OLE Object
Error Contains an error number
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VBScript Overview

7. Variable is a placeholder that refers to a memory location that stores program
information that may change at run time.
Usage:
Referred to by its name for accessing the value stored or to modify its value
Declaration:
Variables are explicitly declared in the script using:
Dim Statement
Public statement
Private statement
Multiple variables can be declared by separating each variable name with a comma.
Examples
Dim intPassngrCnt 'Declaring variable for storing Passenger Count
Dim MyVar, MyNum ' Declare two variables
Naming Convention:
Must begin with an alphabetic character
Cannot contain an embedded period
Must not exceed 255 characters
Must be unique in the scope in which it is declared
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Note:
•Variables declared with Dim at the script level are available to all procedures within the script. At the procedure level,
variables are available only within the procedure.
•Public statement variables are available to all procedures in all scripts.
•Private statement variables are available only to the script in which they are declared
VBScript Overview

8. A constant is a meaningful name that takes the place of a number or a
string, and never changes. VBScript in itself has a number of defined
intrinsic constants like vbOK, vbCancel, vbTrue, vbFalse and so on.
Declaration:
The Const statement is used to create constants.
Using the Const statement, you can create string or numeric constants with
meaningful names and assign them literal values
Const service_class = “Business”
Const No_Passenger = 2
Note that the string literal is enclosed within quotations. Date and time literals
are represented by enclosing them in number signs (#)
Const dt_today = #27-07-2005#
Constants can be declared as Private or Public. These keywords can be
prefixed before the Const keyword to make them act as one.
Private Const CnstAirways=”Blue line Airways”
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Note:
•Constants are public by default.
•Within procedures, constants are always private; their visibility can't be changed.
VBScript Overview

9. Conditional Constructs execute statements or repeat certain set of
statements based on conditions.
The following conditional constructs are available in VBScript
If – Then –Else
Used to evaluate whether a condition is true or false and depending on the result, to specify one or
more statements to execute.
Usually the condition is an expression that uses a comparison operator to compare one value or
variable with another.
Can be nested to as many levels as needed.
Select Case
Is an alternative to If Then Else for selectively executing one block of statements from among multiple
blocks of statements.
A Select Case structure works with a single test expression that is evaluated once, at the top of the
structure. The result of the expression is then compared with the values for each Case in the structure.
If there is a match, the block of statements associated with that Case is executed.
Rwerwerwrrwrw
Werewrwr
Wreew
Werwr
wer
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Advanced QTP 8.0

10. Looping allows to run a group of statements repeatedly. The
loop is repeated based on a condition. The loop runs as long as
the condition is true. The following looping constructs are
available in VBScript.
Do – Loop
Do – Loop Construct is used to execute a block of statements based on a
condition.
The statements are repeated either while a condition is true or until a
condition becomes true.
While Keyword can be used to check a condition in a Do – Loop construct.
The condition can be checked before entering into the loop or after the loop
has run at least once.
Pre-Check Do-Loop Construct
Example:
‘Code starts
Dim intCnt
Intcnt=0
Do while intCnt < 4
msgbox intCnt
intCnt=intCnt+1
Loop
‘Code ends
This will run for how many times?
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VBScript Overview

11. Post-Check Do-Loop Construct
‘Code starts
Dim intCnt
Intcnt=0
Do
msgbox intCnt
intCnt=intCnt+1
Loop while intCnt > 4
‘Code ends
This will run for how many times?
The Do-Loop construct can be terminated before the condition
fails by using the Exit Do statement.
The basic difference between a “Do while – Loop” and “Do -
Loop while” is that the previous one gets executed only when
the condition in the while statement holds true where as a “Do –
Loop while” gets executed atleast once, because the condition in
the while statement gets checked at the end of the first iteration.
While – Wend
This While – Wend Construct is same as the “Do while – Loop”
construct.
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VBScript Overview

12. For … Next Loop
The For-Next loop can be used to run a block of statements a specific number of times.
For loops use a counter variable whose value is increased or decreased with each repetition of the loop.
The Next statement by default increments the counter variable by 1.
Example #1:
‘Code Starts
Dim intCnt
For intCnt=1 to 5 ‘Will initialise the intCnt to 1 & then proceed with the loop condition checking.
Msgbox intCnt
Next ‘Control shifts back to For statement from here with increment of intCnt by 1.
‘Code ends
Output – 1, 2, 3, 4, 5
Example #2:
‘Code Starts
Dim intCnt
For intCnt=1 to 5 Step 2 ‘Will initialise the intCnt to 1 & then proceed with the loop condition checking.
Msgbox intCnt
Next ‘Control shifts back to For statement from here with increment of intCnt by 2.
‘Code ends
Output – 1, 3, 5
The For-Next statement can be terminated before the counter reaches its end value by using the Exit For
statement.
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VBScript Overview

13. An array is a contiguous area in the memory referred to by a common name.
It is a series of variables having the same data type.
Usage:
Arrays are used to store related data values.
An array is made up of two parts, the array name and the array subscript.
The subscript indicates the highest index value for the elements within the array.
Each element of an array has a unique identifying index number by which it can be referenced.
VBScript creates zero based arrays where the first element of the array has an index value of zero.
Declaration:
The Dim statement is used to declare arrays. The syntax for declaring an array is as follows:
Dim ArrayName(subscriptvalue)
Example:
Dim arrStuMarks(6)
This example represents an array which will hold 6 elements.
The first element will be represented as arrStuMarks(0)….and so and the last element will be represented as
arrStuMarks(5).
Dim arrrMultiDimension(4)(3)
This example represents an arrau which will hold 12 elements in all, namely 4 rows constituting of 3
elements each per row.
So the first element of the first row will be arrrMultiDimension(0)(0), first element of the second row will be
represented by arrrMultiDimension(1)(0) and the first element of the last row will be represented by
arrrMultiDimension(3)(0).
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VBScript Overview

14. Assigning Values to Arrays:
arrStuMarks(0)=1 ‘Assigning value to the first element of the arrStuMarks Array
arrStuMarks(3)=2 ‘Assigning value to the fourth element of the arrStuMarks Array
arrrMultiDimension(0)(1)=14 ‘Assigning value to the second element of the first row of the
arrrMultiDimension Array.
Scope:
Local Arrays
A local array is available only within the function or procedure, where it is declared.
Global Arrays
A global array is an array that can be used by all functions and procedures. It is declared at the beginning of
the VBScript code.
Types:
VBScript provides flexibility for declaring arrays as static or dynamic.
Static Arrays
A static array has a specific number of elements.
The size of a static array cannot be altered at run time.
Dynamic Arrays
A dynamic array can be resized at any time.
Dynamic arrays are useful when size of the array cannot be determined.
The array size can be changed at run time.
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‘Code Starts
Dim arrSum(3) ‘Static array
arrSum(0)=2 ‘Assigning values
arrSum(1)=3
‘Code Ends
‘Code Starts
Dim arrSum() ‘Dynamic array
‘Some more code in between
ReDim arrSum(25) ‘declaring dimension to the dynamic array
arrSum(0)=2 ‘Assigning values
arrSum(24)=3
‘Code Ends
VBScript Overview

15. Procedures are set of executable statements, which has been given a name.
In VBScript, there are two types of procedures:
Sub Procedures
Function Procedures
Sub Procedures:
A Series of VBScript statements, enclosed by Sub and End Sub statements.
Do not return a value.
Example:
‘Code starts
PromptUsrName ‘Call to the procedure
Sub PromptUsrName ( ) ‘Procedure definition
Dim strName
strName= inputbox ("Please enter the user name", "Test Project")
Msgbox “Parameter entered by you is ” & strName
End Sub ‘Procedure definition ends
‘Code ends
Function Procedures:
A series of VBScript statements enclosed by the Function and End Function statements.
Can return value to the calling function.
Example:
‘Code starts
Dim intArea
intArea=CalcArea(10,20)‘Calling function CalcArea
Msgbox “The area of the rectangle is “ & intArea
Function CalcArea(intheight, intwidth)‘Function definition
‘Formula for calculating Area and then returning value to the calling statement
CalcArea=intheight * intwidth
End function‘Function ends
‘Code ends
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VBScript Overview

16. VBScript facilitates integration of different interfaces with QTP, like if the
user wants Output of the QTP test on word document OR the user wants to
read an excel sheet which will act as inputs for one of the QTP tests.
VBScript’s object oriented feature strengthens and eases the way to use object
model of any package.
Example for using word with QTP
‘Code starts
SystemUtil.Run "winword","","C:\Documents and Settings\padmashree.raichur",""
Window("Microsoft Word_1").WinObject("Microsoft Word Document").Type _
"This is a good document."
Window("Microsoft Word_1").WinObject("Standard").Click 67,21
Window("Microsoft Word_1").Window("Save As").WinListView("SysListView32").Select "Good"
Window("Microsoft Word_1").Window("Save As").Click 515,325
Window("Microsoft Word_1").Window("Save As").Window("Microsoft Office Word").Click 251,125
Window("Microsoft Word_1").close
‘Code ends
The above mentioned program creates a new word document and writes the text “This is a
good document” and renames it as “good.doc” and then closes the document.
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VBScript Overview

17. Case Study:
We have some scenarios in the excel sheets (Test plans) which
are to be tested.
Also each and every Scenario is having a respective QTP test
scripts already pre-recorded and stored in a particular location.
Now what we need to do is think of a way where in we could
run the testscripts of QTP from the excel sheet itself.
Solution:
Create macros in Excel.
Add a Command button to each scenario on the excel sheet and
call the respective macro thru the same.
In the macros, write the code to call and run the QTP script.
The user will then accordingly put a pass/fail against the
respective testcase in the excel sheet.
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VBScript Overview

18. pgorantla.blogspot.com
Q & A….
VBScript Overview

19. Basics of VBScript include:
Data types
Variables
Constants
Operators
Procedures
Iterative constructs
Conditional Constructs
VBScript has only one data type called a variant.
Variables are declared using the Dim statement, the Public
statement, and the Private statement.
Constants can be created by using the Const statement.
Constants are a number or a string whose value never
changes.
Procedures are of two types:
Sub
Function
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VBScript Overview

20. VBScript has the following conditional constructs:
If – Then – Else statement
Select Case Construct
VBScript has the following iterative constructs:
Do Loop
While-Wend Loop
For-Next
The Exit For statement is used to terminate the For-Next Loop.
The Exit Do statement is used to terminate the Do-Loop.
The basic difference between a “Do while – Loop” and “Do -
Loop while” is that the previous one gets executed only when
the condition in the while statement holds true where as a “Do
– Loop while” gets executed atleast once, because the condition
in the while statement gets checked at the end of the first
iteration.
Different interfaces like Excel, word can be interfaced with QTP
and vice-a-versa using VBScript and the respective object
model of the corresponding interfaces.
pgorantla.blogspot.com
VBScript Overview