PHP服务器端验证正则表达式匹配

Question

I have the following part of a validation script:

$invalidEmailError .= "<br/>&raquo;&nbsp;You did not enter a valid E-mail address";    
$match = "/\b[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}\b/";

That's the expression, here is the validation:

if ( !(preg_match($match,$email)) ) {
    $errors .= $invalidEmailError; // checks validity of email
}

I think that's enough info, let me know if more is needed.

Basically, what happens is the message "You did not enter a valid E-mail address" gets echoed no matter what. Whether a correct email address or an incorrect email address is entered.

Does anyone have any idea or a clue as to why?

EDIT: I'm running this on localhost (using Apache), could that be the reason as to why the preg_match ain't working?

Thanks! Amit

Answer 1

Your regex only includes [A-Z], not [a-z]. Try

$match = "/\b[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}\b/i";

to make the regex case-insensitive.

You can test this live on http://regexpal.com.

However, I'd advise you to try one of the expressions on the page mentioned by strager: http://fightingforalostcause.net/misc/2006/compare-email-regex.php. They have been perfected over time and will probably behave better. But Gmail users will be satisfied with yours, since they'll be able to use plus aliases which are rejected incorrectly by many validators.