Static Statement

See Also9EMG08                 Example57HQ385>Low

Used at the procedure level2W6W4TC to declare variables and allocate storage space.  Variables declared with the Static statement retain their value as long as the program is running.

Syntax

Static varname[([subscripts])] [As [New] type] [, varname[([subscripts])] [As [New] type] ] . . .

Remarks

The Static statement has these parts:

Part                 Description

 

varname           Name of a variable.

subscripts        Dimensions of an arrayYPCGZO.  You can declare multiple dimensions.  The syntax of subscripts is described below.

As type            Reserved word43US84 used to declare the data type3GYXY7 of the variable.  The type may be Integer, Long, Single, Double, Currency, String (for variable-length strings), String * length (for fixed-length strings), Variant8PHEAW3, a user-defined type, or an object type9DGMAH.  Use a separate As type clause for each variable being defined.

New                 Creates a new instance of a specific object type, such as Form1.  The New reserved word cannot be used to create new variables of any of the fundamental data types, nor can it be used to create a variable of any generic object type (MDIForm, Form or Control) or any specific control type (CommandButton, TextBox, and so on).

 

The argument subscripts has the following syntax:

          [lower To ]upper[,[lower To] upper] . . .

The To reserved word provides a way to indicate both the lower and upper bounds of an array variable's subscripts.  The following statements are equivalent if there is no Option Base statement:

  Static A(8,3)

  Static A(0 To 8, 0 To 3)

  Static A(8, 0 To 3)

 

Array subscripts can be negative.  To can be used to specify any range of subscripts between -32,768 and 32,767, inclusive.  For example:

  Static A(-4 To 10)

  Static B(-99 To -5, -3 To 0)

 

The maximum number of array dimensions allowed in a Static statement is 60.

 

If you use a subscript that is greater than the specified maximum or smaller than the specified minimum, an error occurs.

Use the Static statement in nonstatic procedures to explicitly declare Static variables.  You must use Static to declare a fixed-size array in nonstatic procedures.  In Static procedures, you can use either Static or Dim to declare Static variables.

Use a Static statement within a procedure to declare the data type of a Static variable.  For example, the following statement declares a fixed-size array of integers:

  Static EmployeeNumber(200) As Integer

 

Also use the Static statement in Sub or Function procedures to declare the object type of a variable.  The following statement declares a variable for a new instance of a form:

  Static X As New Form1

 

If New is not used when declaring an object variable, no instance of the object actually exists.  The variable must be assigned to an existing object of type using the Set statement before it can be used.  Until it is assigned to an existing object, the declared object variable has the special value Nothing, which indicates that it does not refer to any particular instance of an object.

 

Note   The Static statement and the Static reserved word affect the lifetime of variables differently.  If you declare a procedure using the Static reserved word (as in Static Sub CountSales ()), the storage space for all local variables within the procedure is allocated once and the value of the variables is preserved for the entire time the program is running.  For nonstatic procedures, storage space for variables is allocated each time the procedure is called and released when the procedure is exited.  The Static statement is used to declare variables within nonstatic procedures to preserve their value as long as the program is running.

 

When variables are initialized, numeric variables are initialized to 0, Variant variables to Empty1L2JEZ4.  Variable-length strings are initialized as zero-length strings, and fixed-length strings are filled with zeros.  The fields of user-defined type variables are initialized as if they were separate variables.

 

Tip     When you use the Static statement in a procedure, it is a generally accepted programming practice to put Static statements at the beginning of the procedure with any Dim statements.

 


See Also

Dim StatementLANDIM

Function StatementEZ33BF

Global StatementTDN897

Option Base StatementQH5EUA

ReDim StatementQ1CGU1

Sub StatementLANSUB


Static Statement Example

The example uses the Static statement to declare a persistent variable in the Picture_Click procedure.  To try this example, which also illustrates the action of the Arrange method, paste the code into the Declarations section of an MDI Form named MDIForm1 that has an MDI child form (named Form1), and a picture box (named Picture1).  Then press F5 and click anywhere in the picture box..

 

Const FORMCOUNT = 5

Dim F(1 To FORMCOUNT) As New Form1

Sub MDIForm_Load ()

  Dim I                               ' Declare local variable.

  Load Form1                          ' Load original Form1.

  For I = 1 To FORMCOUNT

    F(I).Caption = "Form" & I + 1     ' Change caption on copies.

    F(I).Show                         ' Load 5 copies of Form1.

  Next I

End Sub

 

Sub Picture1_Click ()

  Static ClickCount As Integer        ' Declare variables.

  Dim I, PrevWidth, Start

  ClickCount = ClickCount + 1         ' Increment click counter.

  Select Case ClickCount

    Case 1

      MDIForm1.Arrange 1              ' Tile horizontally.

    Case 2

      MDIForm1.Arrange 2              ' Tile vertically.

    Case 3                            ' Minimize each form.

      PrevWidth = MDIForm1.Width      ' Get MDIForm width.

      MDIForm1.Width = PrevWidth / 2  ' Divide it in half.

      Form1.WindowState = 1           ' Minimize the original.

      For I = 1 To FORMCOUNT          ' Look at each instance of F.

        If TypeOf F(I) Is Form1 Then

          F(I).WindowState = 1        ' Minimize each copy.

        End If

      Next I

      Start = Timer                   ' Get timer start point.

      Do

      Loop Until Timer >= Start + 5

      MDIForm1.Width = PrevWidth      ' Resize to original size

      MDIForm1.Arrange 3              ' Arrange icons

  End Select

End Sub