Does the ReDim statement intialise String Arrays with empty strings?

Question

Given the following statements in VBA:
Assume that val = 4 and Option Base 0

Dim dataStr() As String
ReDim dataStr(val)

Will the ReDim statement intialise the String array dataStr to 5 empty string elements(0 to 4).
What exactly will be the contents of the Array after the execution of the ReDim statement.

Answer 1

Sub RedimStringArray()

Dim Val As Integer
Dim dataStr() As String
Dim idx As Long

    Val = 4

    ReDim dataStr(Val)

    For idx = LBound(dataStr) To UBound(dataStr)
        Debug.Print idx, """" & dataStr(idx); """", TypeName(dataStr(idx)), Len(dataStr(idx))
    Next

End Sub

gives me this:

 0            ""            String         0 
 1            ""            String         0 
 2            ""            String         0 
 3            ""            String         0 
 4            ""            String         0

So I'd say that yes, ReDim re-initializes the array with empty strings.

Answer 2

Just to confirm the answer from Mike Woodhouse, see section 5.4.3.3 of the VBA Language Specification:

http://msdn.microsoft.com/en-us/library/dd361851%28PROT.10%29.aspx

Each array in a <redim-statement> is resized according to the dimensions specified in its <bounds-list>. Each element in the array is reset to the default value for its data type, unless the word “preserve” is specified.

Answer 3

You could just read the VB6 manual page on ReDim?

When variables are initialized, a variable-length string is initialized to a zero-length string (""), and a fixed-length string is filled with zeros