“Validieren Sie das Textfeld Netbeans E -Mails” Code-Antworten

Validieren Sie das Textfeld Netbeans E -Mails

(?=.{1,64}@)            # local-part min 1 max 64

[A-Za-z0-9_-]+          # Start with chars in the bracket [ ], one or more (+)
                        # dot (.) not in the bracket[], it can't start with a dot (.)

(\\.[A-Za-z0-9_-]+)*	 # follow by a dot (.), then chars in the bracket [ ] one or more (+)
                        # * means this is optional
                        # this rule for two dots (.)

@                       # must contains a @ symbol

[^-]                    # domain can't start with a hyphen (-)

[A-Za-z0-9-]+           # Start with chars in the bracket [ ], one or more (+)     

(\\.[A-Za-z0-9-]+)*      # follow by a dot (.), optional

(\\.[A-Za-z]{2,})       # the last tld, chars in the bracket [ ], min 2