目录

# ReDim 语句

Declares or redefines variables or arrays.

### 语法:

    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.

### 参数:

variable: Any variable or array name.

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

Byte: Byte variable (0-255)

Boolean: Boolean variable (True, False)

Currency: Currency variable (Currency with 4 Decimal places)

「Date」: 日期变量

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

「Integer」: 整数变量 (-32768 到 32767)

「Long」: 长整数变量 (-2,147,483,648 到 2,147,483,647)

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

「Single」: 单精度浮点变量 (3.402823 x 10E38 到 1.401298 x 10E-45)。

String: String variable consisting of a maximum of 2,147,483,647 characters.

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.

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
--- | ---
% | Integer
& | Long
! | Single
# | Double
$ | String
@ | Currency

array: Array declaration.

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 支持用指定的变量类型定义的一维和多维数组。如果要在程序中编辑列表或表格，则使用数组是最合适的，因为可以通过索引定位数组中的各个元素，而索引可以用数字表达式或变量来表述。

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.

## 示例:

    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