minor #9651 Fix extract method to avoid recalculating count() for each iteration. (fabpot)

This PR was submitted for the master branch but it was merged into the 2.2 branch instead (closes #9651).

Discussion
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Fix `extract` method to avoid recalculating count() for each iteration.

This PR was submitted on the symfony/DomCrawler read-only repository and moved automatically to the main Symfony repository (closes symfony/dom-crawler#16).

Cache the value of `count($attributes)` to avoid recalculating it for each iteration of the loop.

Since this count will never change during the method execution, this change make the code a bit more efficient.

Commits
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9ababf4 Fix `extract` method to avoid recalculating count() for each iteration.

Author: fabpot

src/Symfony/Component/DomCrawler/Crawler.php

@@ -504,6 +504,7 @@ public function text()
     public function extract($attributes)
     {
         $attributes = (array) $attributes;
+        $count = count($attributes);
 
         $data = array();
         foreach ($this as $node) {
@@ -516,7 +517,7 @@ public function extract($attributes)
                 }
             }
 
-            $data[] = count($attributes) > 1 ? $elements : $elements[0];
+            $data[] = $count > 1 ? $elements : $elements[0];
         }
 
         return $data;