You can write your own UDF for that like this one:
FUNCTION DigitAll()
LPARAMETERS tlcExpression
LOCAL lnCounter, llDigit
llDigit = .T.
FOR lnCounter = 1 to LEN(tlcExpression)
IF !ISDIGIT(SUBSTR(tlcExpression, lnCounter, 1))
llDigit = .F.
ENDIF
ENDFOR
RETURN llDigit
ENDFUNC
You can also add to this function a check for decimal point.
>I need to check if a whole character expression contains nothing but numeric digits. I thought the isdigit() function would do it but I found out that it just checks the leftmost character. Is there any function like isdigit() that checks the whole expression?
>
>Thank you