ReDim Statement

Declares or redefines variables or arrays.


ReDim Statement diagram

ReDim [Preserve] variable [(start To end)] [As type-name][, variable2 [(start To end)] [As type-name][,...]]

Optionally, add the Preserve keyword to preserve the contents of the array that is redimensioned. ReDim can only be used in subroutines.


variable: Any variable or array name.

typename: Keyword that declares the data type of a variable.

primitive data types fragment

Byte: Byte variable (0-255)

Boolean: Boolean variable (True, False)

Currency: Currency variable (Currency with 4 Decimal places)


Double: Double-precision floating-point variable (1,79769313486232 x 10E308 - 4,94065645841247 x 10E-324)

Integer:整數型變數 (-32768 - 32767)

Long:長型整數變數 (-2.147.483.648 - 2.147.483.647)

Object: Object variable (Note: this variable can only subsequently be defined with Set!)

Single:單精度型浮點變數 (3,402823 x 10E38 - 1,401298 x 10E-45).

String:最多可以含有 64,000 個 ASCII 字元的字串型變數。

Variant: Variant variable type (contains all types, specified by definition). If a type name is not specified, variables are automatically defined as Variant Type, unless a statement from DefBool to DefVar is used.

object: Universal Network object (UNO) object or ClassModule object instance.

char: Special character that declares the data type of a variable.

Type declaration characters fragment

In LibreOffice Basic, you do not need to declare variables explicitly. However, you need to declare arrays before you can use them. You can declare a variable with the Dim statement, using commas (,) to separate multiple declarations. To declare a variable type, enter a type-declaration character following the name or use a corresponding type keyword name.

Declaration character

Variable type name













array: Array declaration.

array fragment

start, end: Numerical values or constants that define the number of elements (NumberElements=(end-start)+1) and the index range.

start and end can be numerical expressions if ReDim is applied at the procedure level.

LibreOffice Basic 支援由指定變數類型定義的一維陣列和多維陣列。如果要在程式中編輯清單或表格,則使用陣列是適宜的。使用陣列的優點是,可用索引定位個別的元素,而該索引又可作為數值型表示式或變數來構成公式。

Arrays are declared with the Dim statement. There are multiple ways to define the index range:

  Dim text(20) As String ' 21 elements numbered from 0 to 20
  Dim value(5 to 25) As Integer ' 21 values numbered from 5 to 25
  Dim amount(-15 to 5) As Currency ' 21 amounts (including 0), numbered from -15 to 5
  REM Two-dimensional data field
  Dim table$(20,2) ' 63 items; from 0 to 20 level 1, from 0 to 20 level 2 and from 0 to 20 level 3.

You can declare an array types as dynamic if a ReDim statement defines the number of dimensions in the subroutine or the function that contains the array. Generally, you can only define an array dimension once, and you cannot modify it. Within a subroutine, you can declare an array with ReDim. You can only define dimensions with numeric expressions. This ensures that the fields are only as large as necessary.


Sub ExampleRedim
    Dim iVar() As Integer, iCount As Byte
    ReDim iVar(5) As Integer
    For iCount = 1 To 5
        iVar(iCount) = iCount
    Next iCount
    ReDim iVar(10) As Integer
    For iCount = 1 To 10
        iVar(iCount) = iCount
    Next iCount
End Sub

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