Question

I want to validate email address in html form. I have very little knowledge in regex.

Validation is very simple, just to match any_symbols@any_symbols.two_to_eight_symbols pattern.

Here is the regex I’m trying to use ^.+@.+\..{2,8}$. Yet it doesn’t work, it validates pattern any_symbols@four_symbols.

Note: do not worry about such simple validation, on server side I’m doing filter_var (php) and sending token to that email. Just need to enable button on form when inputed email address fits some sane pattern 🙂

EDIT Those patterns “any_symbols…” I’ve mentioned in question are just textual representation of what I’m trying to input. This is not what I type in input field 🙂 Usually I type “[e-mail]”, or “[e-mail]” and etc. 🙂

EDIT2 Actuall code:

   var email_regex = new RegExp("^.+@.+\..{2,8}$");
if ($target.val().match(email_regex) !== null){
    $button.removeAttr('disabled').removeClass('disabled');
}
else{
    $button.attr('disabled', 'disabled').addClass('disabled');
}

EDIT3 *Found the problem!* It wasn’t the regex itself, it was how I passed regex to Regex function… it should be

 new RegExp(/^.+@.+\..{2,8}$/);

not the

new RegExp("^.+@.+\..{2,8}$");

As I’ve said this whole regex thing is quite new to me :))

Answer 1

Suposely the regex for a real email address is not quite simple, since it should comply with an RFC standard.

However, if this works for you, I’ve used it with no problems:

// The regex: /^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,4})$/

// To test it:
var regex = new RegExp(/^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,4})$/);

if( regex.test( your_string ) ){ ... } // returns true if valid

If you really need to accept ANY symbols, you can use the regex that Birei posted.