VBScript in a Nutshell, 2nd Edition

Name

Sgn Function

Syntax

Sgn(number)

number

Use: Required

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

A numeric expression.

Return Value

An 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 and 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—a fairly trivial one—is to determine the sign of an expression. It’s equivalent to the following code:

  Function Sgn(varNumber)
     If varNumber > 0 Then
        Sgn = 1
     ElseIf varNumber = 0 Then
        Sgn = 0
     Else
        Sgn = -1
     End If
  End Function

• 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 Statement