Ruby Email validation with regex

Question

I have a large list of emails I am running through. A lot of the emails have typos. I am trying to build a string that will check valid emails.

this is what I have

Answer 1

I guess the example from the book can be improved to match emails with - in subdomain.

VALID_EMAIL_REGEX = /\A[\w+\-.]+@[a-z\d\-]+(\.[a-z\d\-]+)*\.[a-z]+\z/i

For example:

> 'some@email.with-subdomain.com' =~ VALID_EMAIL_REGEX
=> 0

Answer 2

try this!!!

/\[A-Z0-9._%+-\]+@\[A-Z0-9.-\]+\.\[AZ\]{2,4}/i

only email string selected

"Robert Donhan" <bob@email.com>sadfadf
Robert Donhan <bob@email.com>
"Robert Donhan" abc.bob@email.comasdfadf
Robert Donhan bob@email.comadfd

Answer 3

Yours is complicated indeed.

VALID_EMAIL_REGEX = /\A[\w+\-.]+@[a-z\d\-.]+\.[a-z]+\z/i

The above code should suffice.

Explanation of each piece of the expression above for clarification:

Start of regex:

/

Match the start of a string:

\A

At least one word character, plus, hyphen, or dot:

[\w+\-.]+

A literal "at sign":

@

A literal dot:

\.

At least one letter:

[a-z]+

Match the end of a string:

\z

End of regex:

/

Case insensitive:

i

Putting it back together again:

/\A[\w+\-.]+@[a-z\d\-.]+\.[a-z]+\z/i

Check out Rubular to conveniently test your expressions as you write them.

Answer 4

This works good for me:

if email.match?('[a-z0-9]+[_a-z0-9\.-]*[a-z0-9]+@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,4})')
      puts 'matches!'
else
      puts 'it doesn\'t match!'
end

Answer 5

Here's a great article by David Celis explaining why every single regular expression you can find for validating email addresses is wrong, including the ones above posted by Mike.

From the article:

The local string (the part of the email address that comes before the @) can contain the following characters:

    `! $ & * - = ` ^ | ~ # % ' + / ? _ { }` 

But guess what? You can use pretty much any character you want if you escape it by surrounding it in quotes. For example, "Look at all these spaces!"@example.com is a valid email address. Nice.

If you need to do a basic check, the best regular expression is simply /@/.

Answer 6

This has been built into the standard library since at least 2.2.1

URI::MailTo::EMAIL_REGEXP