Is number

[Mark Hunter]

Function NonNegativeWholeNumber(ByVal a As String) As Long      ' Boolean
 Local i As Long

 'exclude strings such as 0000004
 Local b As String                   '
 b = LTrim$(a,"0")                   '
 If a <> "0" And a <> b Then         '
  Function = 0                       '
  Exit Function                      '
 End If                              '
 
 For i = 1 To Len(a)
  If Asc(a, i) < 48 Or Asc(a, i) > 57 Then Exit For
 Next
 Function = (i > Len(a))
End Function

[Mel Bishop]

RETAIN$ would be a lot simpler and shorter. Just RETAIN$ what you want then check the length of the original string vs. processed string. If they are the same, then it's a number. If not....

[Mike Doty]

I should have kept the author's name.

FUNCTION isNumeric(Answer AS STRING) AS LONG
  Answer = TRIM$(Answer) 'may be required if right-justified text
  IF (LEN(Answer) = 0)                  OR _
     (VERIFY (Answer , ".-0123456789")) OR _
     (RIGHT$(Answer,1) = ".")           OR _
     (INSTR(-1,Answer,"-") > 1)         OR _
     (TALLY(Answer,".") > 1) THEN
     EXIT FUNCTION  'exit, return 0 not-numeric
  END IF
  FUNCTION = -1 'numeric
END FUNCTION

[Mel Bishop]

Take a look at RETAIN$.

[David Clarke]

Many years ago there was a function in the language I was using that would return true or false if the string was a number:

MY_STRING = "1234567"
IF MY_STRING IS NBR THEN PRINT "ITS A NUMBER!"

Aside from rolling my own is there a way to do this now in PB / WIN?