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VBScript in a Nutshell, 2nd Edition by Ron Petrusha, Matt Childs, Paul Lomax

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Name

TypeName Function

Syntax

TypeName(varname)
varname

Use: Required

Data Type: Any

The name of a variable.

Return Value

A String.

Description

Returns a string containing the name of the data type of a variable.

Rules at a Glance

  • TypeName returns the variant’s data type. If the variant has not been assigned a value, TypeName returns Empty. Therefore, TypeName never actually returns the string “Variant.”

  • The following table describes the possible return values and their meaning:

Return value

Underlying data type

Boolean

Boolean

Byte

Byte

classname

An object variable of type classname

Currency

Currency

Date

Date

Decimal

Decimal

Double

Double-precision floating-point number

Empty

Uninitialized variable

Error

A missing argument error

Integer

Integer

Long

Long integer

Nothing

A variable of type Object that is not set to a valid object

Null

No valid data

Object

A generic object

Single

Single-precision floating-point number

String

String

Unknown

An object whose type is unknown

Variant( )

An array

VBA/VBScript Differences

  • In VBA, the data type of a strongly typed variable can be ascertained earlier than the data type of a VBScript variable. For instance, in VBA, the code fragment:

    Dim lNumber As Long
    MsgBox TypeName(lNumber)

    indicates that lNumber is a long. The equivalent VBScript code fragment:

    Dim lNumber
    MsgBox TypeName(lNumber)

    indicates that lNumber is Empty, since it hasn’t yet been assigned a value and therefore VBScript cannot determine its data type. (Note that, in VBA, if lNumber is defined as a variant, the behavior of the ...

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