ThinBASIC Core Language > Data types and variables

Variant variables

thinBasic supports VARIANT variables. You can think of a VARIANT as a kind of container, which can hold a variable of most any data type, numeric, string.

You can use a VARIANT variable like all other variables. thinBasic will take care of all needed internal data conversions.

You may determine the type of data a VARIANT variable contains with the VARIANTVT and VARIANTVT$ functions.

The following table summarizes the predefined (built-in) equates that can be used to examine a Variant:

Result	Equate	Meaning
0	%VT_EMPTY	0 or Empty string
1	%VT_NULL	Null string
2	%VT_I2	Integer
3	%VT_I4	Long-integer
4	%VT_R4	Single
5	%VT_R8	Double
6	%VT_CY	Currency
7	%VT_DATE	Date
8	%VT_BSTR	Dynamic string
9	%VT_DISPATCH	Interface reference
10	%VT_ERROR	Error code
11	%VT_BOOL	Boolean
12	%VT_VARIANT	Variant
13	%VT_UNKNOWN
16	%VT_I1	Byte
17	%VT_UI1	Byte
18	%VT_UI2	Word
19	%VT_UI4	DWORD
20	%VT_I8	Quad (signed)
21	%VT_UI8	Quad (unsigned)
22	%VT_INT	Integer
23	%VT_UINT	Word
24	%VT_VOID
25	%VT_HRESULT	COM result code
26	%VT_PTR	Pointer
27	%VT_SAFEARRAY	VB Array
28	%VT_CARRAY
29	%VT_USERDEFINED
30	%VT_LPSTR	ANSI string
31	%VT_LPWSTR	Unicode string
64	%VT_FILETIME
65	%VT_BLOB
66	%VT_STREAM
67	%VT_STORAGE
68	%VT_STREAMED_OBJECT
69	%VT_STORED_OBJECT
70	%VT_BLOB_OBJECT
71	%VT_CF
72	%VT_CLSID	Class ID
&H1000	%VT_VECTOR
&H2000	%VT_ARRAY	Array
&H4000	%VT_BYREF

Internally, a VARIANT is always 16-bytes in size, and may be passed as either a BYVAL or a BYREF parameter to functions.