This document provides an introduction and overview of VBScript, including its data types, variables, operators, and other core concepts. The objectives are to familiarize readers with the VBScript language and teach them how to write client-side scripts using VBScript keywords, operators, functions, arrays, classes, and objects. It covers topics such as VBScript data types, variables, operators, scopes, lifetimes, and statements for declaring variables.

1. Tahir Rashid Hakeem
KSU - Riyadh 1
VBScript
Outline
32.1 Introduction
32.2 Operators
32.3 Data Types and Control Structures
32.4 VBScript Functions
32.5 VBScript Example Programs
32.6 Arrays
32.7 String Manipulation
32.8 Classes and Objects
32.9 Operator Precedence Chart
32.10 Web Resources

2. Tahir Rashid Hakeem
KSU - Riyadh
Objectives
2
• In this tutorial, you will learn:
– To become familiar with the VBScript language.
– To use VBScript keywords, operators and functions to write
client-side scripts.
– To be able to write Sub and Function procedures.
– To use VBScript arrays and regular expressions.
– To be able to write VBScript abstract data types called
Classes.
– To be able to create objects from Classes.
– To be able to write Property Let, Property Get and
Property Set procedures.

3. Tahir Rashid Hakeem
KSU - Riyadh
What is VBScript?
A Safe subset of visual basic
The VBScript Code is case Insensitive.
Microsoft Visual Basic Scripting Edition brings active
scripting to a wide variety of environments, including Web
client scripting in Microsoft Internet Explorer and Web server
scripting in Microsoft Internet Information Service (IIS).
3

4. Tahir Rashid Hakeem
KSU - Riyadh

5. Tahir Rashid Hakeem
KSU - Riyadh
VBScript Data Types
VBScript has only one data type called a Variant.
A Variant is a special kind of data type that can contain different kinds of
information, depending on how it is used.
Because Variant is the only data type in VBScript, it is also the data type
returned by all functions in VBScript.
At its simplest, a Variant can contain either numeric or string information.
A Variant behaves as a number when you use it in a numeric context and as
a string when you use it in a string context.
5

6. Tahir Rashid Hakeem
KSU - Riyadh
VBScript Data Types - Variant
Subtypes
 Beyond the simple numeric or string classifications, a Variant can
make further distinctions about the specific nature of numeric
information.
 For example, you can have numeric information that represents a date
or a time.
 When used with other date or time data, the result is always
expressed as a date or a time.
 You can also have a rich variety of numeric information ranging in size
from Boolean values to huge floating-point numbers.
6

7. Tahir Rashid Hakeem
KSU - Riyadh
VBScript Data Types - Variant
Subtypes
7
Subtype Description
Empty Variant is uninitialized. Value is 0 for numeric variables or a zero-length string ("") for string variables.
Null Variant intentionally contains no valid data.
Boolean Contains either True or False.
Byte Contains integer in the range 0 to 255.
Integer Contains integer in the range -32,768 to 32,767.
Currency -922,337,203,685,477.5808 to 922,337,203,685,477.5807.
Long Contains integer in the range -2,147,483,648 to 2,147,483,647.
Single Contains a 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.
Double Contains a 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.
Date Contains a number that represents a date between January 1, 100 to December 31, 9999.
String Contains a variable-length string that can be up to approximately 2 billion characters in length.
Object Contains an object.
Error Contains an error number.

8. Tahir Rashid Hakeem
KSU - Riyadh
Variables
A variable is a convenient placeholder that refers to a computer
memory location where you can store program information that may
change during the time your script is running.
For example, you might create a variable called ClickCount to store
the number of times a user clicks an object on a particular Web page.
you only have to refer to a variable by his name to see or change its
value.
8

9. Tahir Rashid Hakeem
KSU - Riyadh
Declaring
Variables
You declare variables explicitly in your script using the Dim statement, the
Public statement, and the Private statement. For example:
Dim DegreesFahrenheit
You declare multiple variables by separating each variable name with a
comma. For example:
Dim Top, Bottom, Left, Right
9

10. Tahir Rashid Hakeem
KSU - Riyadh
Declaring
Variables
 You can also declare a variable implicitly by simply using its name in your
script.
 That is not generally a good practice because you could misspell the
variable name in one or more places, causing unexpected results when
your script is run.
 For that reason, the Option Explicit statement is available to require
explicit declaration of all variables.
10

11. Tahir Rashid Hakeem
KSU - Riyadh
Option Explicit Statement
 Forces explicit declaration of all variables in a script.
 If used, the Option Explicit statement must appear in a script
before any other statements.
 When you use the Option Explicit statement, you must
explicitly declare all variables using the Dim, Private, Public, or
ReDim statements. If you attempt to use an undeclared
variable name, an error occurs.
 Tip Use Option Explicit to avoid incorrectly typing the name
of an existing variable or to avoid confusion in code where the
scope of the variable is not clear.
11

12. Tahir Rashid Hakeem
KSU - Riyadh
Naming Restrictions
 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.
12

13. Tahir Rashid Hakeem
KSU - Riyadh
VBScript Keywords
Empty
◦ The Empty keyword is used to indicate an uninitialized variable value.
Null
◦ The Null keyword is used to indicate that a variable contains no valid data.
True
◦ The True keyword has a value equal to -1.
False
◦ The False keyword has a value equal to 0.
Nothing
◦ The Nothing keyword in VBScript is used to disassociate an object variable from
any actual object.
13

14. Tahir Rashid Hakeem
KSU - Riyadh
Scopes and Lifetimes
 A variable's scope is determined by where you declare it.
 When you declare a variable within a procedure, only code within that
procedure can access or change the value of that variable.
 If you declare a variable outside a procedure, you make it recognizable
to all the procedures in your script.
 The lifetime of a variable depends on how long it exists.
 The lifetime of a script-level variable extends from the time it is
declared until the time the script is finished running.
 At procedure level, a variable exists only as long as you are in the
procedure.
 we can have local variables of the same name in several different
procedures because each is recognized only by the procedure in which
it is declared.
14

15. Tahir Rashid Hakeem
KSU - Riyadh
Dim Statement
Dim varname[([subscripts])][, varname[([subscripts])]] . . .
Declares variables and allocates storage space.
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.
You can also use the Dim statement with empty parentheses to declare a
dynamic array.
Note When you use the Dim statement in a procedure, you generally put
the Dim statement at the beginning of the procedure.
15

16. Tahir Rashid Hakeem
KSU - Riyadh
Private Statement
Private varname[([subscripts])][, varname[([subscripts])]] . . .
Declares private variables and allocates storage space.
Private statement variables are available only to the script in which they are
declared.
The following example illustrates use of the Private statement:
16
Private MyNumber ‘--- Private Variant variable.
Private MyArray(9) ‘--- Private array variable.
‘--- Multiple Private declarations of Variant variables.
Private MyNumber, MyVar, YourNumber

17. Tahir Rashid Hakeem
KSU - Riyadh
Public Statement
Public varname[([subscripts])][, varname[([subscripts])]] . . .
Declares public variables and allocates storage space.
Public statement variables are available to all procedures in all scripts.
You can also use the Public statement with empty parentheses to declare a
dynamic array.
17
Public MyNumber ‘--- Public Variant variable.
Public MyArray(9) ‘--- Public array variable.
‘--- Multiple Public declarations of Variant variables.
Public MyNumber, MyVar, YourNumber

18. Tahir Rashid Hakeem
KSU - Riyadh
Rem Statement
 Includes explanatory remarks in a program.
Rem Comment
‘ Comment
 As shown in the syntax section, you can use an apostrophe (') instead of the Rem
keyword.
 If the Rem keyword follows other statements on a line, it must be separated from
the statements by a colon.
 However, when you use an apostrophe, the colon is not required after other
statements.
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MyStr1 = "Hello" : Rem Comment after a statement separated by a colon.MyStr1 = "Hello" : Rem Comment after a statement separated by a colon.
MyStr2 = "Goodbye" ' This is also a comment; no colon is needed.MyStr2 = "Goodbye" ' This is also a comment; no colon is needed.
Rem Comment on a line with no code; no colon is needed.Rem Comment on a line with no code; no colon is needed.

19. Tahir Rashid Hakeem
KSU - Riyadh
Assigning Values to Variables
Values are assigned to variables creating an expression as follows:
◦the variable is on the left side of the expression and the value you want to
assign to the variable is on the right.
For Example :
19
B = 200B = 200

20. Tahir Rashid Hakeem
KSU - Riyadh
Operators
20
• Types of operators
– Arithmetic
• Most are similar to JavaScript’s
– Logical
– Comparison
• VBScript is case-insensitive

21. Tahir Rashid Hakeem
KSU - Riyadh
Mathematic Operators
21
VBScript operation Arithmetic operator Algebraic expression VBScript expression
Addition + x + y x + y
Subtraction - z – 8 z – 8
Multiplication * yb y * b
Division (floating-point) / v u or <Anchor0> v / u
Division (integer) none v u
Exponentiation ^ q p q ^ p
Negation - –e —e
Modulus Mod q mod r q Mod r

22. Tahir Rashid Hakeem
KSU - Riyadh
Comparison
Operators
22
Standard algebraic
equality operator or
relational operator
VBScript
comparison
operator
Example of
VBScript
condition
Meaning of VBScript
condition
= = d = g d is equal tog
< > s < > r s is not equal tor
> > y > x y is greater thanx
< < p < m p is less thanm
≥ >= c >= z C is greater than or equal toz
<= m <= s m is less than or equal tos≤
≠

23. Tahir Rashid Hakeem
KSU - Riyadh
Logical Operators
23
Truth tables for VBScript Logical Operators
Logical And:
True And True= True
True And False =False
False And True =False
False And False =False
Logical Or:
True Or True = True
True Or False = True
False Or True = True
False Or False =False
Logical Imp:
True Imp True= True
True Imp False =False
False Imp True =True
False Imp False =True
Logical Eqv:
True Eqv True= True
True Eqv False =False
False Eqv True =False
False Eqv False =True
Logical Xor:
True Xor True = False
True Xor False =True
False Xor True =True
False Xor False =False
Logical Not:
Not True = False
Not False = True

24. Tahir Rashid Hakeem
KSU - Riyadh
Control Structures
24
• Looping
– While…Wend and Do While…Loop
• Analogous to JavaScript’s while statement
– Do…Loop While
• Analogous to JavaScript’s do…while statement
– Do…Until Loop and Do…Loop Until
• No direct equivalent in JavaScript
• Repeat until loop-continuation condition is true
– For
• Condition cannot be modified mid-loop
• Optional Step keyword
– Exit Do and Exit For
• Break out of loops

25. Tahir Rashid Hakeem
KSU - Riyadh
Examples Looping Control
Structures
25
JavaScript VBScript
1 while ( !( x == 10 ) )
2 ++x;
1 Do Until x = 10
2 x = x + 1
3 Loop
Comparing JavaScript’s while to VBScript’s Do Until.
JavaScript VBScript
1 do {
2 ++x;
3 } while ( !( x == 10 ) );
1 Do
2 x = x + 1
3 Loop Until x = 10
Comparing JavaScript’s do...while to VBScript’s Do Loop...Until.
JavaScript VBScript
1 x = 8;
2 for ( y = 1; y < x; y++ )
3 x /= 2;
1 x = 8
2 For y = 1 To x
3 x = x 2
4 Next
Comparing JavaScript’s for to VBScript’s For.

26. Tahir Rashid Hakeem
KSU - Riyadh
Decision Control
Statements
26
Making Decisions Using If...Then...Else
The If...Then...Else statement is used to evaluate whether a condition is True
or False and then to specify one or more statements to run, depending on the
result.
Usually, the condition is an expression that uses a comparison operator to
compare one value or variable with another.
If...Then...Else statements can be nested to as many levels as you need.

27. Tahir Rashid Hakeem
KSU - Riyadh
VBScript Functions
27
 A function is a group of reusable code which can be called
anywhere in your program.
 This eliminates the need of writing same code over and over again.
This will enable programmers to divide a big program into a
number of small and manageable functions.
 Apart from inbuilt Functions, VBScript allows us to write user-
defined functions as well.

28. Tahir Rashid Hakeem
KSU - Riyadh 28
Before we use a function, we need to define that particular function.
The most common way to define a function in VBScript is by using the Function
keyword, followed by a unique function name and it may or may not carry a list of
parameters and a statement with a End Function keyword, which indicates the end of
the function.
The basic syntax is shown below:
Function
Definition

29. Tahir Rashid Hakeem
KSU - Riyadh 29
Function
Example

30. Tahir Rashid Hakeem
KSU - Riyadh
Calling a Function
30
To invoke a function somewhere later in the script, you would simple need to
write the name of that function with the Call keyword.

31. Tahir Rashid Hakeem
KSU - Riyadh
VBScript Functions
31
Function
Variant
subtype
returned
Description
IsArray Boolean
Returns True if the variant subtype is an array and False
otherwise.
IsDate Boolean
Returns True if the variant subtype is a date or time and
False otherwise.
IsEmpty Boolean
Returns True if the variant subtype is Empty (i.e., has not
been explicitly initialized by the programmer) and False
otherwise.
IsNumeric Boolean
Returns True if the variant subtype is numeric and False
otherwise.
IsObject Boolean
Returns True if the variant subtype is an object and False
otherwise.
TypeName String
Returns a string that provides subtype information. Some
strings returned are "Byte", "Integer", "Long", "Single",
"Double", "Date", "Currency", "String", "Boolean" and
"Empty".
VarType Integer
Returns a value indicating the subtype (e.g., 0 for Empty, 2
for integer, 3 for long, 4 for single, 5 for double, 6 for
currency, 7 for date/time, 8 for string, 9 for object, etc.).
Some variant functions.

32. Tahir Rashid Hakeem
KSU - Riyadh
VBScript Functions
32
• Math functions
– VBScript provides many functions for common operations
• Exponential
• Logarithmic
• Square root
• Rounding
• Absolute value
• Trigonometry
• Random number generation

33. Tahir Rashid Hakeem
KSU - Riyadh
VBScript Math
Functions
33
Function Description Example
Abs(x)
Absolute value of x Abs(-7) is 7
Abs(0) is 0
Abs(76) is 76
Atn(x)
Trigonometric arctangent of x
(in radians)
Atn(1)*4 is
3.14159265358979
Cos(x) Trigonometric cosine of x (in radians) Cos(0) is 1
Exp(x) Exponential function ex
Exp(1.0) is 2.71828
Exp(2.0) is 7.38906
Int(x)
Returns the whole-number part of x. Int
rounds to the next smallest number.
Int(-5.3) is –6
Int(0.893) is 0
Int(76.45) is 76
Fix(x)
Returns the whole-number part of x
[Note: Fix and Int are different. When x is
negative, Int rounds to the next
smallest number, while Fix rounds to the
next-largest number.]
Fix(-5.3) is –5
Fix(0.893) is 0
Fix(76.45) is 76
Log(x) Natural logarithm of x (base e) Log(2.718282) is 1.0
Log(7.389056) is 2.0
Rnd()
Returns a pseudo-random floating-point
number in the range 0 Rnd < 1. Call
function Randomize once before calling Rnd
to get a different sequence of random
numbers each time the program is run.
Call Randomize
...
z = Rnd()
VBScript math functions.
≤

34. Tahir Rashid Hakeem
KSU - Riyadh
VBScript Math
Functions
34
Function Description Example
Round(x, y)
Rounds x to y decimal places. If y is
omitted, x is returned as an integer.
Round(4.844) is 5
Round(5.7839, 2) is 5.78
Sgn(x) Sign of x
Sgn(-1988) is –1
Sgn(0) is 0
Sgn(3.3) is 1
Sin(x) Trigonometric sine of x (in radians) Sin(0) is 0
Sqr(x) Square root of x
Sqr(900.0) is 30.0
Sqr(9.0) is 3.0
Tan(x) Trigonometric tangent of x (in radians) Tan(0) is 0
VBScript math functions.

35. Tahir Rashid Hakeem
KSU - Riyadh
VBScript Functions
35
• Formatting functions
– Currency
– Dates and times
– Numbers
– Percentages

36. Tahir Rashid Hakeem
KSU - Riyadh
Functions
36
Function Description
FormatCurrency
Returns a string formatted according to the local machine’s currency Regional
Settings (in the Control Panel). For example, the call FormatCurrency("-1234.789")
returns "($1,234.79)" and the call FormatCurrency(123456.789) returns "$123,456.79".
Note the rounding to the right of the decimal place.
FormatDateTime
Returns a string formatted according to the local machine’s date/time Regional
Settings (in the Control Panel). For example, the call FormatDateTime(Now,
vbLongDate) returns the current date in the format "Wednesday, September 01,
1999" and the call FormatDateTime(Now, vbShortTime) returns the current time
in the format "17:26". Function Now returns the local machine’s time and date.
Constant vbLongDate indicates that the day of the week, month, day and year is
displayed. Constant vbShortTime indicates that the time is displayed in 24-hour
format. Consult the VBScript documentation for additional constants that specify
other date and time formats.
FormatNumber
Returns a string formatted according to the number Regional
Settings (in the Control Panel) on the local machine. For example, the call
FormatNumber("3472435") returns "3,472,435.00" and the call FormatNumber(-
123456.789) returns
"-123,456.79". Note the rounding to the right of the decimal place.
FormatPercent
Returns a string formatted as a percentage. For example the call
FormatPercent(".789") returns "78.90%" and the call
FormatPercent(0.45) returns "45.00%".
Some VBScript formatting functions.

37. Tahir Rashid Hakeem
KSU - Riyadh
String Manipulation
37
• Strings
– Case sensitive in VBScript
– Most string manipulation functions do not modify original
• Return new string with modifications

38. Tahir Rashid Hakeem
KSU - Riyadh
String Manipulation
38
Function Description
Asc Returns the ASCII numeric value of a character. For
example, Asc("x") returns 120.
Chr Returns the character representation for an ASCII value.
For example, the call Chr(120) returns “x.” The
argument passed must be in the range 0 to 255 inclusive,
otherwise an error occurs.
InStr Searches a string (i.e., the first argument) for a substring
(i.e., the second argument). Searching is performed from
left to right. If the substring is found, the index of the
found substring in the search string is returned. For
example, the call Instr("sparrow","arrow") returns 3,
and the call Instr("japan","wax") returns 0.
Len Returns the number of characters in a string. For example,
the call Len("hello") returns 5.
LCase Returns a lowercase string. For example, the call
LCase("HELLO@97[") returns “hello@97[.”
UCase Returns an uppercase string. For example, the call
UCase("hello@97[") returns “HELLO@97[.”
Left Returns a string containing characters from the left side of
a string argument. For example, the call
Left("Web",2) returns “We.”
Mid Function Mid returns a string containing a range of
characters from a string. For example, the call
Mid("abcd",2,3)returns “bcd.”
Right Returns a string containing characters from the right side
of a string argument. For example, the call
Right("Web",2) returns “eb.”
Space Returns a string of spaces. For example, the call
Space(4) returns a string containing four spaces.
Fig. 32.19 Some string-manipulation functions.

39. Tahir Rashid Hakeem
KSU - Riyadh
String Manipulation
39
Function Description
StrComp
Compares two strings for equality. Returns 1 if the first string is greater
than the second string, returns -1 if the first string is less than the second
string and returns 0 if the strings are equivalent. The default is a binary
comparison (i.e., case sensitive). An optional third argument of
vbTextCompare indicates a case-insensitive comparison. For example,
the call StrComp("bcd", "BCD") returns 1, the call
StrComp("BCD", "bcd") returns -1, the call StrComp("bcd",
"bcd") returns 0 and the call StrComp("bcd", "BCD",
vbTextCompare) returns 0.
String
Returns a string containing a repeated character. For example, the call
String(4,"u")returns “uuuu.”
Trim
Returns a string that does not contain leading or trailing space
characters. For example, the call Trim(" hi ") returns
“hi.”
LTrim Returns a string that does not contain any leading space characters. For
example, the call LTrim(" yes") returns “yes.”
RTrim Returns a string that does not contain any trailing space characters. For
example, the call RTrim("no ") returns “no”.
Filter
Returns an array of strings containing the result of the Filter
operation. For example, the call
Filter(Array("A","S","D","F","G","D"),"D") returns a
two-element array containing "D" and "D", and the call
Filter(Array("A","S","D","F","G","D"),"D",False)
returns an array containing "A" , "S", "F" and "G".
String manipulation functions.

40. Tahir Rashid Hakeem
KSU - Riyadh
String Manipulation Functions
40
Function Description
Join
Returns a string containing the concatenation of array elements
separated by a delimiter. For example, the call
Join(Array("one","two","three")) returns “one two
three.” The default delimiter is a space which can be changed by
passing a delimiter string for the second argument. For example, the
call Join(Array("one","two","three"),"$^") returns
“one$^two$^three.”
Replace
Returns a string containing the results of a Replace operation.
Function Replace requires three string arguments—the string where
characters will be replaced, the substring to search for and the
replacement string. For example, Replace("It's Sunday and the sun
is out","sun","moon") returns “It's Sunday and the moon
is out.” Note the case-sensitive replacement.
Split
Returns an array containing substrings. The default delimiter for
Split is a space character. For example, the call Split("I met a
traveller") returns an array containing elements "I", "met", "a" and
"traveller", and Split("red,white,and blue", ",") returns an array
containing elements "red", "white" and "and blue". The optional
second argument changes the delimiter.
StrReverse Returns a string in reverse order. For example, the call
StrReverse("deer") returns “reed.”
String manipulation functions.

41. Tahir Rashid Hakeem
KSU - Riyadh
String Manipulation
41
• Translating to Pig Latin
– Uses string methods
• Split
• InStr
• LCase
• Left

42. Tahir Rashid Hakeem
KSU - Riyadh
VBScript Interactive Functions
42
• User interaction
– InputBox
• Displays dialog that accepts input
intValue = InputBox( "Enter an integer",
"Input Box", , 1000, 1000 )
– MsgBox
• Displays message dialog
• Customizable buttons and icon
Call MsgBox( "VBScript is fun!", , "Results" )

43. Tahir Rashid Hakeem
KSU - Riyadh
Arrays
43
• Arrays
– Related data items of same type
– Fixed size or dynamic
• Also “redimmable”
– Made up of individual elements
• Accessed via array name, parentheses and index number
• Start at position zero
• Declaring arrays
– Keyword Dim
– Name
– Highest valid index
• Upper bound

44. Tahir Rashid Hakeem
KSU - Riyadh
Arrays
44
• Examples
– Declaring array with three elements
Dim numbers( 2 )
– Assigning values to each element
numbers(0) = 77
numbers(1) = 68
numbers(2) = 55

45. Tahir Rashid Hakeem
KSU - Riyadh
Arrays
45
• Examples, cont.
– Declaring array and using For loop to fill with values
• Fills with multiples of 3 from 0 through 30
Dim h( 11 ), x, i
i = 0
For x = 0 To 30 Step 3
h(i) = CInt( x )
i = CInt( i ) + 1
Next

46. Tahir Rashid Hakeem
KSU - Riyadh
Arrays
46
• Array dimensions
– UBound and LBound functions
• LBound is always zero
• Access modifiers
– Public vs. Private
• Public default
• Dynamic arrays
– Keyword ReDim
• Keyword Preserve
• Allocating arrays larger than original vs. smaller than original
– Keyword Erase

47. Tahir Rashid Hakeem
KSU - Riyadh
Arrays
47
• Multidimensional arrays
– Like normal arrays
• Rows and columns rather than just columns
– UBound and LBound still work
• Dimension is second argument
– Can be fixed size or created dynamically

48. Tahir Rashid Hakeem
KSU - Riyadh
Arrays
48
• Examples of multidimensional arrays
– Declaring two- and three-dimensional arrays
Dim b(2, 2), tripleArray(100, 8, 15)
– Determining upper bound of third dimension
For x = 0 To UBound(tripleArray, 3)
– Dynamically allocating three-dimensional array
ReDim threeD(11, 8, 1)

49. Tahir Rashid Hakeem
KSU - Riyadh
Classes and Objects
49
• Object-based programming
– Objects have data and behavior
– Information hiding
• Not necessary to know internal details to use class
• Allows class internals to be replaced/upgraded
without breaking code that uses class
– Objects model real-world entities
• Makes programs easier to understand
– Promotes reusability
– Objects are instances of classes
• Class can have many objects existing at same time

50. Tahir Rashid Hakeem
KSU - Riyadh
Classes and
Objects
50
• Objects in VBScript
– Keyword Class
– Methods
• Procedures that belong to class
– Instance variables
• Exist only inside class

51. Tahir Rashid Hakeem
KSU - Riyadh
Classes and Objects
51
• Abstract data-types
– Powerful feature for simplifying programs
– Represented as classes
– Describe data in terms of behavior
– Instance variables should be Private
• Allow access through methods
• Ensure integrity and consistency
• Property Let, Property Get, Property Set
• Exit Property

52. Tahir Rashid Hakeem
KSU - Riyadh
Classes and
Objects
52
• Property Set
– Use for basic Variant sub-type variables
Public Property Set BirthDay(bDay)
Set mBirthDate = bDay
End Property
Public Property Get BirthDay()
Set BirthDay = mBirthDate
End Property

53. Tahir Rashid Hakeem
KSU - Riyadh
Operator Precedence Chart
53
Operator Type
() parentheses
- unary minus
^ exponentiation
*
/
multiplication
division
integer division
Mod modulus
+
-
addition
subtraction
& string concatenation
=
<>
<
<=
>
>=
Is
equality
inequality
less than
less than or equal
greater than
greater than or equal
object equivalence
Not logical NOT
And logical AND
Or logical OR
Xor logical exclusive OR
Eqv logical equivalence
Imp logical implication