>>If you mean in a VFP app, it should be pretty easy. Spin through the string, looking at each character. Keep a running count of how many are ISDIGIT(), ISUPPER() and ISLOWER(). You have a strong password if:
>>
>>( LEN() >= 6 ) AND( DigitCount >= 1 ) AND ( NonDigitCount >= 2 ) AND ( UpperCount >= 1 ) AND ( LowerCount >= 1 )
>
>I doänt understand the need for NonDigitCount. Is the following code best way to check for a strong password ?
>
>

FUNCTION IsStrongPassword( cStr )
>
>LOCAL i, nDigitCount, nUpperCount, nLowerCount
>STORE 0 TO nDigitCount, nUpperCount, nLowerCount
>FOR i=1 TO LEN(cStr)
>  DO case
>    CASE ISDIGIT( SUBSTR(m.cStr,m.i))
>      nDigitCount = nDigitCount + 1
>
>    CASE ISUPPER(SUBSTR(m.cStr,m.i))
>      nUpperCount = nUpperCount + 1
>
>    CASE ISLOWER(SUBSTR(m.cStr,m.i))
>      nLowerCount = nLowerCount + 1
>    ENDCASE
>ENDFOR
>
>RETURN LEN(m.cStr)>5 AND m.nUpperCount>0 AND m.nLowerCount>0

How about something like this - might be faster than loops.

LPARAMETERS tcPwd
LOCAL lcDigit, lcAlpha, llStrong

llStrong = .F.
lcDigit = "0123456789"
lcAlpha = "abcdefghijklmnopqrstuvwxyz"

IF LEN(tcPWd) > 5 AND ;
   LEN(tcPwd) <> LEN(CHRTRAN(tcPwd, lcDigit, "")) AND ;
   LEN(tcPwd) <> LEN(CHRTRAN(tcPwd, UPPER(lcAlpha), "")) AND ;
   LEN(tcPwd) <> LEN(CHRTRAN(tcPwd, LOWER(lcAlpha), ""))
	
   llStrong = .T.
ENDIF

RETURN llStrong