Data Type Determination

hey, guys - a quick question. I'm writing a DLL to incorporate a lot of common programming tasks that I perform, such as determining max and mins, means, averages, concatenating strings, establishing and maintaining ADO Connections, and such. In certain parts of the dll, I need to know what data type I'm working with. If I'm reading in a variant, is there any way to determine, at run time, what I have. I know there is the "IsNumeric" boolean function, but.. if I wanted to know if it was an integer, character, string, double, etc... are there intrinsic functions to do that?

You can use the TypeName() function...

see DevGuru - TypeName for syntax.

Cheers,
HTH

Hi fisherman!It's deeply problem that i have be puzzled by it for long time..MS vb provide some function to do it,but their function is not enough to us.I think it will be worked out by Ms programer or ourselves!It's very significative to VB developers.Some body can support this mine!?~Let's Do it Now?!

Thx for Doug G!
VarType Function

Returns an Integer indicating the subtype of a variable.

Syntax

VarType(varname)

The required varname argument is a Variant containing any variable except a variable of a user-defined type.

Return Values

Constant Value Description
vbEmpty 0 Empty (uninitialized)
vbNull 1 Null (no valid data)
vbInteger 2 Integer
vbLong 3 Long integer
vbSingle 4 Single-precision floating-point number
vbDouble 5 Double-precision floating-point number
vbCurrency 6 Currency value
vbDate 7 Date value
vbString 8 String
vbObject 9 Object
vbError 10 Error value
vbBoolean 11 Boolean value
vbVariant 12 Variant (used only with arrays of variants)
vbDataObject 13 A data access object
vbDecimal 14 Decimal value
vbByte 17 Byte value
vbUserDefinedType 36 Variants that contain user-defined types
vbArray 8192 Array


Note These constants are specified by Visual Basic for Applications. The names can be used anywhere in your code in place of the actual values.

This example uses the VarType function to determine the subtype of a variable.

Dim IntVar, StrVar, DateVar, MyCheck
' Initialize variables.
IntVar = 459: StrVar = "Hello World": DateVar = #2/12/69#
MyCheck = VarType(IntVar) ' Returns 2.
MyCheck = VarType(DateVar) ' Returns 7.
MyCheck = VarType(StrVar) ' Returns 8.