VB & VBA in a Nutshell: The Language

Sgn Function

Named Arguments

No

Syntax

Sgn(number)

number

Use: Required

Data Type: Numeric

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 and Gotchas

• I suppose that someone, somewhere, has found a really good use for the Sgn function. However, its usefulness escapes me, because you need to carry out a test on the return value of the function identical to that which you could use on the number to find its sign.

• 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)

See Also

If...Then Statement