Re: Negative string offsets

it is retard, but it makes the most sense.. On 2014-04-17 17:25, Rasmus Lerdorf wrote:

On 04/17/2014 08:07 AM, Johannes Schlüter wrote:

On Thu, 2014-04-17 at 17:18 +0300, Andrey Andreev wrote:

For example, every time you need to check for a filename extension, last segment of a path, etc. When I need that, I always endup with substr(), strrchr() or explode(), end() ... both are suboptimal.

I don't see where this helps in that case.

         $sep = strrpos($filename, ".");
         if ($sep !== false) {
             $ext = substr($filename, $sep + 1);
         }

is clear and concise, two fcalls, can be understood even after years and the new programmer easily. This is the most concise form I came up using this new offset:

         $ext = '';
         $pos = -1;
         do {
             $ext = $filename[$pos].$ext;
         } while ($filename[--$pos] != '.');

While this form is bugged as it assumes that there is a . without checking. For checking I'd have to use strlen(), but if i call strlen() I can also initialize $pos accordingly and iterate from strlen() to 0. Also this form does more comparisons and way more allocations and is (in my opinion) way harder to understand. Maye I didn't see a simple form ...

Yeah, it wouldn't make any sense unless it supported ranges. Something like: if($filename[-4,4] === '.ext') ... although, I don't see how that is better than: if(substr($filename,-4) === '.ext') ... The latter is much clearer. -Rasmus