Declaring Array Variables

Arrays in a Basic Control Engine script are declared using any of the following statements:

  Dim

  Public

  Private

For example:

  Dim a(10) As Integer

  Public LastNames(1 to 5,-2 to 7) As Variant

  Private

Arrays of any data type can be created, including Integer, Long, Single, Double, Boolean, Date, Variant, Object, user-defined structures, and data objects.

The lower and upper bounds of each array dimension must be within the following range:

  -32768 <= bound <= 32767

Arrays can have up to 60 dimensions.

Arrays can be declared as either fixed or dynamic, as described below.

Fixed Arrays

The dimensions of fixed arrays cannot be adjusted at execution time. Once declared, a fixed array will always require the same amount of storage. Fixed arrays can be declared with the Dim, Private, or Public statement by supplying explicit dimensions. The following example declares a fixed array of ten strings:

 Dim a(10) As String

Fixed arrays can be used as members of user-defined data types. The following example shows a structure containing fixed-length arrays:

  Type Foo

    rect(4) As Integer

    colors(10) As Integer

  End Type

Only fixed arrays can appear within structures.

Dynamic Arrays

Dynamic arrays are declared without explicit dimensions, as shown below:

  Public Ages() As Integer

Dynamic arrays can be resized at execution time using the Redim statement:

  Redim Ages$(100)

Subsequent to their initial declaration, dynamic arrays can be redimensioned any number of times. When redimensioning an array, the old array is first erased unless you use the Preserve keyword, as shown below:

 Redim Preserve Ages$(100)

Dynamic arrays cannot be members of user-defined data types.

Passing Arrays

Arrays are always passed by reference.

Querying Arrays

The following table describes the functions used to retrieve information about arrays.

Use this function

to

LBound

Retrieve the lower bound of an array. A runtime error is generated if the array has no dimensions.

UBound

Retrieve the upper bound of an array. A runtime error is generated if the array has no dimensions.

ArrayDims

Retrieve the number of dimensions of an array. This function returns 0 if the array has no dimensions

Use this command

to

ArraySort

Sort an array of integers, longs, singles, doubles, currency, Booleans, dates, or variants.

FileList

Fill an array with a list of files in a given directory.

DiskDrives

Fill an array with a list of valid drive letters.

AppList

Fill an array with a list of running applications.

SelectBox

Display the contents of an array in a list box.

PopupMenu

Display the contents of an array in a pop-up menu.

ReadIniSection

Fill an array with the item names from a section in an ini file.

FileDirs

Fill an array with a list of subdirectories.

Erase

Erase all the elements of an array.

ReDim

Establish the bounds and dimensions of an array.

Dim

Declare an array.

A