ReDim Instruction

Syntax
ReDim [Preserve] vardeclaration [As type][, ...]
Group
Declaration
Description
Redimension a dynamic arrayvar or user defined type array element. Use Preserve to keep the array values. Otherwise, the array values will all be reset. When using preserve only the last index of the array may change, but the number of indexes may not. (A one-dimensional array can't be redimensioned as a two-dimensional array.)
See Also
Dim, Option Base, Private, Public, Static

Sub Main
    Dim X()
    ReDim X(3)
    Debug.Print UBound(X) ' 3
    ReDim X(200)
    Debug.Print UBound(X) ' 200
End Sub