String validation

[rushenas]

I want to validate a string, and it must only contains alphabetic characters. But using below code, it doesn't work. Can anyone tell me why?

              if (!eregi("[[:alpha:]]", $_REQUEST["name"]))
                  echo "Error";

[Weedpacket]

Because your code is only checking to see if it contains a letter - never mind what any of the rest of it is.

You should look to see if it contains a nonletter - if it does, then it fails.

[mrhappiness]

Weedpacket wrote:

You should look to see if it contains a nonletter - if it does, then it fails.

or you have it check if it contains only letters, from the start to the very end

[Weedpacket]

Which (given random input) is more than twice as slow on average....

[mrhappiness]

$search = array_merge(range('a', 'z'), range('A', 'Z'));
  if (str_replace($search, '', $string_to_check)
    die('Only letters allowed');

maybe it's faster than ereg or preg 😉

didn't know that checking the way i suggested is that slow
why is that?

[drew010]

i think simple regex is a bit faster in that case. i tested it and its like a whole 2/10,000 faster lol.

if (preg_match('/[^\w]/', $string_to_check)) echo 'only letters';