How to count maximum values inside text box?

[toplisek]

I like to count number of characters inside text box.
1. How to do it with PHP to echo it or/and
2. limit it to maximum with warning and/or
3. how to set it with automatic Javascript code when user filled text box?

Need help.

[007Julien]

In my opinion, the best solution consists in using regular expressions...
With javascript, the single following lines count characters (we remove all other characters before).

// For lower or upper case letters  
var result=str.replace(/[^a-z]+/gim,'').length;
// For lower word characters depending of the local setting  
var result=str.replace(/[\W]+/gim,'').length;
// For lower word or digits characters  
var result=str.replace(/[\W\D]+/gim,'').length;

It is the same thing with PHP

$str=preg_replace("/[^a-z]+/gi","",$str);
$result=strlen($str);// Or mb_strlen($str); with character encoding