Array help containing characters

[crazyg]

I' looking to write a e-mail address validator in php before the address gets inserted into my database.

I allready started an want to use the in_array function.

At the moment I use three range functions then merge the arrays together.

I was wondering if the was a more elegant way of populating my array with all lowercase letter, numbers 0 to 9, dashes, underscores and @ signs.

Any help would be most welcome.

[Installer]

That way seems pretty elegant to me. But if by "elegant" you mean fewest lines:

$ok_arr = array_merge(range('a', 'z'), range('0', '9'), array('@', '_'));

[liquorvicar]

would some kind of regexp be better than the method you're suggesting?
i always use this email validator:

function check_email($email) {
	$regex =
	  '^'.
	  '[_a-z0-9-]+'.        /* One or more underscore, alphanumeric, 
	                           or hyphen charactures. */
	  '(\.[_a-z0-9-]+)*'.   /* Followed by zero or more sets consisting 
	                           of a period and one or more underscore, 
	                           alphanumeric, or hyphen charactures. */
	  '@'.                  /* Followed by an "at" characture. */
	  '[a-z0-9-]+'.         /* Followed by one or more alphanumeric 
	                           or hyphen charactures. */
	  '(\.[a-z0-9-]{2,})+'. /* Followed by one or more sets consisting 
	                           of a period and two or more alphanumeric 
	                           or hyphen charactures. */
	  '$';

if (!(eregi($regex, $email))) {
	return 0;
} else {
	return 1;
}
}

[Installer]

For a quick, not-too-picky validator, you could easily do without regular expressions. For serious validation, they're probably indispensible.

I wasn't suggesting any method (if you mean me), only answering the question about building an array.

Edit: I like your way of commenting regexps.

[liquorvicar]

thanks for the compliment 😉 but it's not actually my code. if i remember, i lifted it from the PHP manual's annotations section (probably the eregi page). but i agree, the comments are nice.

wouldn't regexps be better even if you wanted a simpler form of validation? i don't know what the performance difference would be between in_array and a simple eregi() or preg_match() call.

[Installer]

IMO (please remember that), the possible performance costs are outweighed by readability and maintainability gains with simpler tasks, unless perhaps you're looping through thousands at a time. Also, according to php.net and some of my own non-expert tests, with less stringent tasks the string functions are faster.

Not to mention that I've seen people put many person-hours into debugging regular expression that are no faster or little faster or exacting than string function routines. Some do it for the learning and some because they're pre-convinced.

[crazyg]

Thanx for all your replies, it is much appreciated.

The Regular Expressions does seem to give you more controll over how the string should be formated. In the function I wrote it would be exceptable to use the @sign twice, witch is realisticly not permisable.

So from all you comments I will use the regular expressions and try to write a function using strings to do the same as the regex can do.

Cheers

Crazy G