VBScript in a Nutshell

Name

Sgn Function

Syntax

Sgn(number)

number

Use: Required

Data Subtype: Any expression capable of conversion into a numeric value

A numeric expression.

Return Value

A Variant of subtype Integer.

Description

Determines the sign of a number.

Rules at a Glance

The return value of the Sgn function is determined by the sign of number:

If Number is...	Sgn Returns
Positive	1
Zero	0
Negative	-1

Programming Tips & Gotchas

• If you’re planning on using the Sgn function to evaluate a result to False (0) or True (any nonzero value), you could also use the CBool function.

• The major use for Sgn—and a fairly trivial one—is to determine the sign of an expression. It’s equivalent to the following code:

  Public Function Sgn(varNumber as Variant) as Integer
  
  If varNumber > 0 Then
     Sgn = 1
  ElseIf varNumber = 0 Then
     Sgn = 0
  Else
     Sgn = -1
  End If

• Sgn is useful in cases in which the sign of a quantity defines the sign of an expression. For example:

  lngResult = lngQty * Sgn(lngValue)

• Although Sgn handles the conversion of strings to numeric data, it’s a good idea to make sure that number is valid by calling the IsNumeric function before the call to Sgn.

See Also

If . . . Then . . . Else Statement