SBasic language reference::Dim statement

Dim statement
Used to declare and allocate storage space for variables and arrays.

Format:

  Dim name[ (boundlist) ] [ As type ]

Syntax:

name
Required. Name of the variable. Must be a valid SBasic identifier. You can declare as many variables as you like in the same declaration statement, specifying the name part for each one and supplying the boundlist part for arrays. Multiple variables are separated by commas.

You can declare several variables to be of the same data type. You can also specify different types for different variables or groups of variables. Each variable takes the data type specified in the first As clause encountered after its name part.
boundlist
Optional. List of non-negative integers representing the upper bounds of the dimensions of an array variable. Multiple upper bounds are separated by commas. An array can have up to 3 dimensions.

Each value in boundlist specifies the upper bound of a dimension, not the length. The lower bound is always zero, so the subscript for each dimension can vary from zero through the upper-bound value (including upper-bound value!).
type
Optional. Data type of the variable. Can be Integer, Floating or String; or the name of structure. You can use a separate As clause for each variable being defined, or you can define several variables to be of the same type by using a common As clause.

If you do not specify type, the variable can always change its type. If you do specify type, the data assigned to variable always converted to its type.

Example:

  ' Declare variable s. It can change its type freely
  Dim s
  
  Dim Number As Integer
  Dim MyInt1, MyInt2 As Integer
  Dim MyInt As Integer, MyFloat As Floating

  ' Array declarations
  Dim MyArray(50) ' Array of 50 elements

  ' Matrix is a two-dimensional array of type Integer.
  Dim Matrix(3, 4) As Integer 

  ' Matrix3 is a three-dimensional array of type Floating.
  Dim Matrix3(5, 9, 5) As Floating