check if password is strong using swift

strong password

/*
 check if the password lenght more than or equal 8
 and have  lowercase , uppercase ,decimalDigits and special characters like !@#$%^&*()_-+ is optional
 
  Why i not use regular expression ?
  Because it's difficult to support  reserved characters in regular expression syntax.
 */

func isValidated(_ password: String) -> Bool {
    var lowerCaseLetter: Bool = false
    var upperCaseLetter: Bool = false
    var digit: Bool = false
    var specialCharacter: Bool = false

    if password.characters.count  >= 8 {
        for char in password.unicodeScalars {
            if !lowerCaseLetter {
                lowerCaseLetter = CharacterSet.lowercaseLetters.contains(char)
            }
            if !upperCaseLetter {
                upperCaseLetter = CharacterSet.uppercaseLetters.contains(char)
            }
            if !digit {
                digit = CharacterSet.decimalDigits.contains(char)
            }
            if !specialCharacter {
                specialCharacter = CharacterSet.punctuationCharacters.contains(char)
            }
        }
        if specialCharacter || (digit && lowerCaseLetter && upperCaseLetter) {
            //do what u want
            return true
        }
        else {
            return false
        }
    }
    return false
}
let isVaildPass:Bool = isValidated("Test**00+-")
print(isVaildPass)