php - 看不懂阿里云盾的代码补丁建议

Question

139c139,140
+       $arr['num'] = intval($arr['num']);
+       $arr['id'] = intval($arr['id']);
267c268
---
270c271,272
+       $arr['id'] = intval($arr['id']);
+       $arr['type'] = addslashes($arr['type']);
308c310
---
+       $arr['id'] = intval($arr['id']);

给出的补丁是这样, 看了下diff, 没明白 ---是什么作用?