sub mytest
GlobalScope.BasicLibraries.loadLibrary("ScriptForge")
Dim dataRow() as integer
dataRow = array()
ReDim dataRow(0 to 1) as integer
dataRow(0) = 1
print dataRow(0)
end sub
It print a empty window,no “1” in the window,
First dataRow is an empty array,i redim it with “ReDim dataRow(0 to 1) as integer”, why can’t print its element after assign value ?
(First, some nitpicks. The GlobalScope.BasicLibraries.loadLibrary("ScriptForge") is completely unnecessary in your example, and only distracts. Also, if you want a single-element array, you should use (0 to 0) - otherwise, what your unused element is intended for in the demo?)
This is a complex bug.
dataRow at each line (I know that everyone doing any programming uses debugger and watch window, right?), you will see that dataRow is Integer(0 to -1) after its Dim statement; it is Variant(0 to -1) after assignment of array(); and it is Empty(0 to 1) after ReDim. The final type of elements is, as told, Empty - and that is the type that can only one possible value: Empty. You can assign any value to it; and the result is still Empty. This is what happens in your case.array(), it starts working. The difference is that it doesn’t have to change the type of elements, so it is Integer(0 to 1) after ReDim, meaning that elements store assigned numbers as expected.array(), try to change the element type - either in Dim, or in ReDim. And this time, the code will fail compilation, with message “BASIC syntax error. Variable dataRow already defined.”. This shows, that you can not re-define the type of elements.(Some?) problems are:
ReDim, when you can’t actually change it?Array function)?ReDim such an indirectly defined array with another element type, and why does it not fail, but silently assigns a different type?While this is a topic for a bug report, the expected use is that you don’t use ReDims that change the element type of arrays.
The Redim operator is very often used in LO Basic programs, so the possibilities to change its behavior are limited.
I think that specifying the type of a variable in Redim is only allowed when the variable is first defined (in the absence of Option Explicit). In other cases, the type specification construct should, alas, be silently ignored.
As far as I understand, Empty is a subtype of Variant.
Every type is a subtype of Variant, in the sense that values of that type can be stored in a variable of type Variant. Empty is not an exception; however, type Empty itself is a fixed type.
We can write
Dim var as Long
but we can’t
Dim var as Empty
IMHO, Empty is not a data type. It is the default value of a variant.
more confusing for the reader, and the interpreter 
it works without.
or rather use :
dataRow = array(1234)
print dataRow(0)
→ 