password-validation.js

/^(?=.*[A-z])(?=.*[A-Z])(?=.*[0-9])(?=.*[$@])(?!.*[iIoO])\S{6,12}$/

/^ // Start of the string.
(?=.*[A-z]) // must contains a characters (lowercase or uppercase characters).
(?=.*[a-z]) // must contains one lowercase characters.
(?=.*[A-Z]) // must contains one uppercase characters.
(?=.*[0-9]) // must contains one digit from 0-9.
(?=.*[$@]) // must contains one special symbols in this list $ and @.
(?!.*[iIoO]) // match any charcuter except i I o and O.
\S{6,12} // length at least 6 characters and a maximum of 12.
$/ // End of the string.