email address validation in JavaScript using regular expression

Question

I'm currently trying to validate email address using regular expression in JavaScript. These are the requirements of the Email address:

The email field contains a user name part follows by "@" and a domain name part.
The user name contains word characters including hyphen ("-") and period (".").
The domain name contains two to four parts of alphabet characters word extension.
Each word extension is separated by a period (".") and the last extension must have two to three characters.

Among four requirements, the third one is most confusing to me. I will be very appreciate if someone can help me. Thank you.

I have tried the first answer in this page, but this answer accept even 5 or more extensions, so it doesn't meet my third requirement.

`the last extension must have two to three characters` - old school, you'll exclude many new TLD's — Jaromanda X, Oct 11 '15 at 13:29
Your requirements are *wrong*, and will reject many valid email addresses. — user229044, Oct 11 '15 at 13:35
Why can't you adapt it then? We don't trade in custom-fitted code, mostly. At least it's not part of the mission. — Deduplicator, Oct 11 '15 at 16:44

score 1 · Accepted Answer · answered Oct 11 '15 at 13:34

For Javascript, here is the regex you need which follows the RFC 5322 standard:

/^[-a-z0-9~!$%^&*_=+}{\'?]+(\.[-a-z0-9~!$%^&*_=+}{\'?]+)*@([a-z0-9_][-a-z0-9_]*(\.[-a-z0-9_]+)*\.(aero|arpa|biz|com|coop|edu|gov|info|int|mil|museum|name|net|org|pro|travel|mobi|[a-z][a-z])|([0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}))(:[0-9]{1,5})?$/i

Side note: it is better to use a very weak regex (basically just matching the '@') and sending a confirmation email.

email address validation in JavaScript using regular expression

1 Answers1