优化车位编号返回

app/Models/ParkingSpaceCamera.php

@@ -83,8 +83,11 @@ class ParkingSpaceCamera extends Model
         foreach ($space_ids as $space_id) {
             $space_number_arr[] = ParkingSpace::getNumber($space_id);
         }
-        return $is_implode ? implode(',', $space_number_arr)
-            : $space_number_arr;
+        if ($is_implode) {
+            return $space_number_arr ? implode(',', $space_number_arr) : '';
+        } else {
+            return $space_number_arr;
+        }
     }
 
     public static function getSpaceCount($camera_id): int