# 演示：以多态取代条件表达式

&#x20;[![](https://400663568-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-Lqv3pBA2yhlz152GoUY%2F-LrEmrEGfqKTgIMXMFUh%2F-LrEmtlXk08HnjCKvU3V%2Fclick-me.png?generation=1571149294948038\&alt=media)](https://github.com/linesh-simplicity/refactoring-course/tree/cd71df4b98dc3d18b07cd87c0e116d21531fdf0c/content/rose/videos/1-polymorphism-480p.mov)
