零散知识点

1、readonly(运行时常量)与const(编译时常量)  https://blog.csdn.net/vc43vc/article/details/82935809

2、装箱与拆箱 https://www.cnblogs.com/liqingwen/p/6486332.html

3、重载、重构、重写 https://blog.csdn.net/wrs120/article/details/53764347

4、事前触发器、事后触发器、行级触发器、语句触发器、数据操作语言（DML）触发器、数据定义语言（DDL）触发器 　　　　      https://www.cnblogs.com/feiquan/archive/2018/04/01/8685722.html 

5、String、StringBuffer、StringBuilder有什么区别？https://baike.baidu.com/item/String%20StringBuilder/22119161    https://zhidao.baidu.com/question/128409742.html

 6、数据库存储过程和函数优缺点，分别能返回几次值？https://www.cnblogs.com/yanghuahui/p/9085461.html，https://blog.csdn.net/u010843421/article/details/81662346，

7、public、private、protected、interal区别？https://www.cnblogs.com/yezongjie/p/20181121AccessRights.html

 8、类和接口的区别？https://www.cnblogs.com/binyao/p/4891306.html，https://www.cnblogs.com/lvxiangjack/p/10449013.html