How to find DataType of a Variable with VBScript?

When you are validating application using our tool QTP, there will be scenarios to check the displayed value in the field is numeric/text/date etc,.The data type of a variable can be identified in two vbscript built-in functions.

1. Vartype
2. Typename

Vartype returns a numeric value indicating the sub datatype of a variable.

The below table contains return values that indicate respective subtypes.

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

Ex:
Dim x
x=10
msgbox vartype(x) 'Returns 2
In the above table 2 indicates vbInteger datatype.So x is an integer type.

Typename directly returns the name of the Sub Datatype of a variable.

SubDatatype	Description
Byte	Byte value
Integer	Integer value
Long	Long integer value
Single	Single-precision floating-point value
Double	Double-precision floating-point value
Currency	Currency value
Decimal	Decimal value
Date	Date or time value
String	Character string value
Boolean	Boolean value; True or False
Empty	Unitialized
Null	No valid data
< object type >	Actual type name of an object
Object	Generic object
Unknown	Unknown object type
Nothing	Object variable that doesn't yet refer to an object instance
Error	Error

Ex:
Dim x
x=10
msgbox typename(x)  'Returns “Integer”

There are some more VBScript Built-in functions to find whether a variable datatype is specific datatype or not.

IsArray -- Returns a Boolean value indicating whether a variable is an array or not.
IsDate -- Returns a Boolean value indicating whether an expression can be converted to a date.
IsEmpty -- Returns a Boolean value indicating whether a variable has been initialized.
IsNull -- Returns a Boolean value that indicates whether an expression contains no valid data (Null).
IsNumeric -- Returns a Boolean value indicating whether an expression can be evaluated as a number.
IsObject -- Returns a Boolean value indicating whether an expression references a valid Automation object.

Built in functions are available for only these datatypes. You can write built function for every datatype like below…
'@@@@@@@@@@@@@@@@@@@@@@
Function IsString(oValue)
  If vartype(oValue)=8 then
    IsString=true
  Else
    IsString=False
  End If
End Function
'@@@@@@@@@@@@@@@@@@@@@@