Category

Keywords

Array handling

Array
-Returns a Variant containing an array

Dim A      ' Declare array

A = Array(50,20,30) ' Store 3 element

B = A(2)   ' B is now 30.

Dim
-Declares variables and allocates storage space.

Dim Names(9)       ' Declare an array with 10 elements.

Dim Names()        ' Declare a dynamic array.

Dim MyVar, MyNum   ' Declare two variables.

Private
-Declares private variables and allocates storage space

Private MyNumber     ' Private Variant variable.

Private MyArray(9)   ' Private array variable.

   ' Multiple Private declarations of Variant variables.

Private MyNumber, MyVar, YourNumber

Public
-Declares public variables and allocates storage space

Public MyNumber     ' Public Variant variable.

Public MyArray(9)   ' Public array variable.

   ' Multiple Public declarations of Variant variables.

Public MyNumber, MyVar, YourNumber

ReDim
-Declares dynamic-array variables, and allocates or reallocates storage space at procedure level.

Dim X(1)             ' Declare Array variable for 2 elements.
ReDim X(10)          ' Redimension for 11 elements.

ReDim Preserve X(15) ' Redim for 16 with preserve old value

IsArray
-Returns a Boolean value indicating whether a variable is an array

Dim MyVariable

Dim MyArray(3)

MyArray(0) = "Sunday"

MyArray(1) = "Monday"

MyArray(2) = "Tuesday"

MyVariable = IsArray(MyArray) ' MyVariable contains "True".

Erase
-Reinitializes the elements of fixed-size arrays and deallocates dynamic-array storage space

Dim NumArray(9)

Dim DynamicArray()

ReDim DynamicArray(9)   ' Allocate storage space.

Erase NumArray   ' Each element is reinitialized.

Erase DynamicArray   ' Free memory used by array.

LBound
-Returns the smallest available subscript for the indicated dimension of an array.

The lower bound for any dimension is always 0.

UBound
-Returns the largest available subscript for the indicated dimension of an array.

Dim B(200,3,4)

Assignments

Set
-Assigns an object reference to a variable or property, or associates a procedure reference with an event.

Set fso = CreateObject("Scripting.FileSystemObject")

Set d = fso.GetDrive(fso.GetDriveName(drvPath))

Comments

Comments using ' or Rem
-Includes explanatory remarks in a program.

Dim MyStr1, MyStr2

MyStr1 = "Hello" : Rem Comment after a statement separated by a colon.

MyStr2 = "Goodbye" ' This is also a comment; no colon is needed.

Rem Comment on a line with no code; no colon is needed.

Constants/Literals

Empty
-The Empty keyword is used to indicate an uninitialized variable value. This is not the same thing as Null

Nothing
-The Nothing keyword in VBScript is used to disassociate an object variable from any actual object

Null
-The Null keyword is used to indicate that a variable contains no valid data. This is not the same thing as Empty

True
-The True keyword has a value equal to -1.

False
-The False keyword has a value equal to 0.

Control flow

Do...Loop
-Repeats a block of statements while a condition is True or until a condition becomes True.

   Dim Counter

   Counter = 0                ' Initialize variables.

   Do While Counter < 30      ' loop Condition.

      Counter = Counter + 1   ' Increment Counter.

      If Counter = 15 Then    ' If condition is True...

         Exit Do              ' Exit loop.

      End If

   Loop

For...Next
-Repeats a group of statements a specified number of times.

For I = 1 To 10

      For J = 1 To 10

            For K = 1 To 10

            . . .

            Next

      Next

Next

For Each...Next
-Repeats a group of statements for each element in an array or collection.

   Dim fso, f, f1, fc, s

   Set fso = CreateObject("Scripting.FileSystemObject")

   Set f = fso.GetFolder(folderspec)

   Set fc = f.Files

   For Each f1 in fc

      s = s & f1.name

      s = s & "<BR>"

   Next

   ShowFolderList = s

If...Then...Else
-Conditionally executes a group of statements, depending on the value of an expression.

If A > 10 Then
    B = A + 5
else
    B = A + 10
End If

Select Case
-Executes one of several groups of statements, depending on the value of an expression.

Dim Color, MyVar

Sub ChangeBackground (Color)

   MyVar = lcase (Color)

   Select Case MyVar

      Case "red"     document.bgColor = "red"

      Case "green"   document.bgColor = "green"

      Case "blue"    document.bgColor = "blue"

      Case Else      MsgBox "pick another color"

   End Select

End Sub

While...Wend
-Executes a series of statements as long as a given condition is True.
 
Dim Counter

Counter = 0   ' Initialize variable.

While Counter < 20   ' Test value of Counter.

   Counter = Counter + 1   ' Increment Counter.

   Alert Counter

Wend   ' End While loop when Counter > 19.

With
-Executes a series of statements on a single object.

With MyLabel

   .Height = 2000

   .Width = 2000

   .Caption = "This is MyLabel"

End With