I don't follow some of the logic - could someone clarify?

public function getCombinedIngredients() 
    {
       $ingredients = [];
       foreach ($this->recipes as $recipe) {
           foreach ($recipe->getIngredients() as $ing) {
               $item = $ing['item'];
               // if item string contains a ','
               if (strpos($item, ',')) {
                   // select string BEFORE (using true boolean) the ',' (if i wanted AFTER the ',' don't use true boolean)
                   $item = strstr($item, ',', true);
               }

// START OF LOST FEELING!

               // if item is plural (contain an 's' on the end)
               if (in_array($item.'s', $ingredients)) {
                   $item .= 's';
               } elseif (in_array(substr($item, 0, -1), $ingredients)) {
                   $item = substr($item, 0, -1);
               }

// END OF LOST FEELING!

               $ingredients[$item] = [
                   $ing['amount'],
                   $ing['measure'],
               ];
           }
       }
       return $ingredients;
    }