VBScript Variables, Implicit Declaration of Data Types, What is VBScript Variable?, Assign Values to Variables, and Declare & Use Variables.
VBScript Variables are variants, they can hold any type of data throughout the program. VBScript supports the implicit and explicit declaration of variables.
Variables in VBScript
1. What is a Variable?
2. Declaration of variables
3. Implicit and Explicit variables.
4. Assigning Values to Variables
5. Purpose of Variables
6. Variable Naming Restrictions
7. Scope of Variables
8. Types of Variables
1. What is a Variable?
A named memory location to store the data.
In a computer environment, there are two types of memory
i) Primary memory: RAM
ii) Secondary memory: HDD, CD-ROM, DVD, USB Drive, etc.
> Variables store in Primary Memory (RAM).
2. Declaration of variables
> using either Public or Private or Dim statements, we can declare Variables.
Ex:
Dim a
Dim x, y, z
Or
Dim x
Dim y
Dim z
3. Implicit and Explicit variables.
Ex:
Dim a
a = 100 ‘Explicit
b = 200 ‘Implicit
Msgbox a + b
———————
Dim Tickets, Price, Total
Tickets = 7
Price = 100
Total = Tickets * Priee
Msgbox Total ‘0 (Incorrect output)
———–
Option Explicit
Dim Tickets, Price, Total
Tickets = 7
Price = 100
Total = Tickets * Priee
Msgbox Total ‘Error
Option Explicit – It forces declaration of all variables in a Script
4. Assigning Values to Variables
Assigning Values to Variables is two types
i) Initialization
ii) Reading
Example:
Dim num1, num2
num1 = 100 ‘Initialization
num2 = InputBox (“Enter Num2 value”) ‘ Reading
Msgbox num1 + num2
5. Purpose of Variables
Dim a, ord
‘Holding the data
a = 100
Msgbox a
‘Storing the data that returned by a Function
a = Now
Msgbox a
‘Storing the data that returned by a program
a = (10 ^ 3)*2
Msgbox a
‘storing object Reference
Set a = CreateObject(“Scripting.FileSystemObject”)
‘As parameter
For ord = 1 To 5 Step 1
Window(“Flight Reservation”).Activate
Window(“Flight Reservation”).WinButton(“Button”).Click
Window(“Flight Reservation”).Dialog(“Open Order”).WinCheckBox(“Order No.”).Set “ON”
Window(“Flight Reservation”).Dialog(“Open Order”).WinEdit(“Edit”).Set ord
Wait 2
Window(“Flight Reservation”).Dialog(“Open Order”).WinButton(“OK”).Click
Next
6. Variable Naming Restrictions
i) Variable names should start with Alfa bytes
Ex:
Dim abc ‘Correct
Dim a12 ‘Correct
Dim 1ab ‘Incorrect
ii) Should not contain embedded periods
Ex:
Dim abc ‘Correct
Dim ab c ‘Incorrect
Dim ab.c ‘Incorrect
Dim ab*c ‘Incorrect
Dim ab_c ‘Correct
—-
iii) Must not exceed 255 characters
1 to 255
———-
iv) Must be unique in the scope of the declaration.
Dim a, b, c ‘Correct
Dim d, e ‘Correct
Dim f, g, A ‘Incorrect
7. Scope of Variables
i) Script Level Variables
They can be used for the entire script.
ii) Function Level Variables
They can be used within the Functions only
Example:
———–
Dim a, b, c ‘Script level variables
a = 10
b = 20
c = a + b
Msgbox c ’30
Function xyz()
Dim d, e ‘Function level variables
d = 40
e = a + d
Msgbox e ’50
End Function
Call xyz()
Dim f, g ‘Script level variables
f = 70
g = b + d + f
Msgbox g ’90
——————————
Option Explicit
Dim a, b, c ‘Script level variables
a = 10
b = 20
c = a + b
Msgbox c ’30
Function xyz()
Dim d, e ‘Function level variables
d = 40
e = a + d
Msgbox e ’50
End Function
Call xyz()
Dim f, g ‘Script level variables
f = 70
g = b + d + f
Msgbox g ‘Error
8. Types of Variables
i) Scalar Variable
To store one value at a time, Value may vary throughout the Execution.
ii) Array Variable
To store series of values at a time based on size of the Array.
Declare Array variable:
Dim a, b(3)
b(0) = 10
b(1) = “abcd”
b(2) = 1.34
b(3) = 40
a = b(0) + b(3)
Msgbox a ’50
——————
Dim a, b(3)
b(0) = 10
b(1) = “abcd”
b(2) = 1.34
b(3) = 40
b(4) = 50 ‘Error
a = b(0) + b(3)
Msgbox a ’50
———————————-
Dynamic Array
Dim a, b(3), c()
ReDim c(3)
c(0) = 10
c(1) = 20
c(2) = 30
c(3) = 40
a = c(1) + c(2)
Msgbox a ’50
ReDim c(5)
c(4) = 50
c(5) = 60
a = c(3) + c(5)
Msgbox a ’60
————————
Use Preserve keyword
Dim a, b(3), c()
ReDim c(3)
c(0) = 10
c(1) = 20
c(2) = 30
c(3) = 40
a = c(1) + c(2)
Msgbox a ’50
ReDim Preserve c(5)
c(4) = 50
c(5) = 60
a = c(3) + c(5)
Msgbox a ‘100
————————————
Dimensional Arrays
———————-
Dim a, b(3), c(), d(4, 5)
d(0, 0) = 10
Assigning series of Values at a time to Array variables
a) Using Array Function
Dim a
Msgbox IsArray(a) ‘False
a = Array(100, “VBScript”, 20, 30, 40, #10/10/2010#)
Msgbox IsArray(a) ‘True
Msgbox a(1) ‘VBScript
Msgbox UBound(a) ‘5
b) Using Split Function
Dim a, b
a = “VB Script Language”
msgbox isArray(b) ‘False
b = Split(a)
Msgbox IsArray(b) ‘True
Msgbox b(1) ‘Script
Msgbox UBound (b) ‘2
———————-
Dim a, b
a = “VB,Script,Language”
msgbox isArray(b) ‘False
b = Split(a, “,”)
Msgbox IsArray(b) ‘True
Msgbox b(1) ‘Script
Msgbox UBound (b) ‘2
————————–
Dim a, b
a = “VB@Script@Language”
msgbox isArray(b) ‘False
b = Split(a, “@”)
Msgbox IsArray(b) ‘True
Msgbox b(1) ‘Script
Msgbox UBound (b) ‘2
—————————-
Dim a, b
a = “VB@%$Script@%$Language”
msgbox isArray(b) ‘False
b = Split(a, “@%$”)
Msgbox IsArray(b) ‘True
Msgbox b(1) ‘Script
Msgbox UBound (b) ‘2
——————————–
Note: In Split Function default delimiter is space, we can use any value as a delimiter, but we need to specify the delimiter.z
