length Function

::---------------------------------------------------------------------------------------
:: Get the length of a string or number
::
:: call :length "Hello World" varName
:: echo %varName%
::---------------------------------------------------------------------------------------
:length
    setlocal
        set "str=X%~1"
        set length=0
        for /L %%a in (8,-1,0) do (
            set /a "length|=1<<%%a"
            for %%b in (!length!) do if "!str:~%%b,1!" equ "" set /a "length&=~1<<%%a"
        )
    (endlocal
        if "%~2" neq "" ( set "%2=%length%" ) else echo %length%
    )
goto :eof
::---------------------------------------------------------------------------------------