Regular Expression for email validation fails

Question

Below regular expression for email validation,

^[a-zA-Z0-9][\w\.-]*[a-zA-Z0-9]@[a-zA-Z0-9][\w\.-]*[a-zA-Z0-9]\.[a-zA-Z][a-zA-Z\.]*[a-zA-Z]$

Here I couldn't understand the [\w\.-] purpose. Can any one please let me know?

Use this pattern,

If I give [email protected] in a email field, validation becomes fail. In email string before @ if just one character or numeric comes the validation become fail. Is this right?

Regards, karthik

This is for Javascript? BTW, the regex looks wrong for its purpose. Where did you get it from? This would be a proper regular expression for email address validation. — rubber boots
– rubber boots, Commented Jul 23, 2012 at 9:50
why people want to use regex for e-mail validation? there are enough libraries for this task — gaussblurinc
– gaussblurinc, Commented Jul 23, 2012 at 9:58
@loldop: Can you please tell me libraries other than regex for email validation? — Karthik
– Karthik, Commented Jul 23, 2012 at 10:22
@Karthik yeah, i can: metacpan.org/module/Email::Valid. This is perl solution. — gaussblurinc
– gaussblurinc, Commented Jul 23, 2012 at 11:06

Tim Pietzcker · Accepted Answer · 2012-07-23 10:01:30Z

2

[\w.-] means a single character that is either:

A word character (alphanumeric or _)
.
-

[email protected] fails because this regular expression requires at least 2 characters before the @.

edited Jul 23, 2012 at 10:01

Tim Pietzcker

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answered Jul 23, 2012 at 10:00

Max Nanasy

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3 Comments

tripleee Over a year ago

The trivial fix would be to change [\w\.-]*[a-zA-Z0-9] into ([\w.-]*[a-zA-Z0-9])? i.e. make the part after the first character optional (and remove the superfluous backslash in the character class).

Max Nanasy Over a year ago

@tripleee I can't tell from the original question whether rejecting [email protected] is desirable or not :P.

tripleee Over a year ago

Ah, maybe the question is really "should I fix this"? Yes, you should.

Shiridish · Accepted Answer · 2012-07-23 11:07:46Z

Use this regular expression for validating email id. Works fine for me

\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*

Mark as answer if that worked for you :)

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