Data types VBScript

VBScript has only one data type called a Variant. It is a special kind of the data type that can contain different kinds of information, depending on how it's used. Because Variant is the only data type in VBScript, it's also the data type returned by all functions in VBScript.
At its simplest, a Variant can contain numeric or string information. A Variant behaves as a number when you use it in a numeric context and as a string when you use it in a string context. That is, if you're working with data that looks like numbers, VBScript assumes that it is numbers and does the thing that is most appropriate for numbers. Similarly, if you're working with data that can only be string data, VBScript treats it as string data. Of course, you can always make numbers behave as strings by enclosing them in quotation marks ("").

Variant Subtypes:
Beyond the simple numeric or string classifications, a Variant can make further distinctions about the specific nature of numeric information. For example, you can have numeric information that represents a date or a time. When used with other date or time data, the result is always expressed as a date or a time. Of course, you can also have a rich variety of numeric information ranging in size from Boolean values to huge floating-point numbers. These different categories that can be contained in a Variant are called subtypes.

The following table shows the subtypes of data that a Variant can contain:

subtype	Description
Boolean	Logical value: true (numeric value is "nonzero", usually -1) or false (numeric value is 0) See the notes below.
Byte	Integer (1 byte) in the range: 0 to 255.
Integer	Integer (2 bytes) in the range: -32768 to 32767.
Long	Integer (4 bytes) in the range: -2,147,483,648 to 2,147,483,647. Hexadecimal value of number can be entered directly by preceding numbers in the proper range with &H. For example, &H10 in hexadecimal represents decimal 16.
Single	Real number (4 bytes) with the precision 7 digits in the range: -3.402823E38 to -1.401298E-45 (negative number). 1.401298E-45 to 3.402823E38 (positive number). Binary implementation format is according to standard IEEE-754 (32-bit)
Double	Real number (8 bytes) with the precision 15 digits in the range: -1.79769313486231E308 to -4.94065645841247E-324 (negative number). 4.94065645841247E-324 to 1.79769313486231E308 (positive number). Binary implementation format is according to standard IEEE-754 (64-bit)
Date	Value containing Date and time. See the notes below.
String	Text string that can be up to approximately 2 billion characters in length in the Unicode character set.
Object	"pointer" (reference) to object.
Array	Array of values. See How to use array of values in the PROMOTIC system.
Empty	Flag that value is uninitialized.
Null	Flag that value contains no valid data.
Nothing	Flag that value contains no valid object.

For conversion of the data into another data subtype, the conversion VBScript functions can be used: CBool, CByte, CInt, CLng, CSng, CDbl, CDate, CStr.
For testing if the variable can be evaluated in the subtype, the following VBScript functions can be used: IsNumeric, IsDate, IsObject, IsEmpty, IsNull, IsArray. By the functions VarType and TypeName it is possible to find out the subtype of the variable. Although it is better to use the Pm.GetVarType and Pm.IsValid methods.