Always prompts 404 error, stuck for a day, what's going on guys, please help, thank you! !
光阴似箭催人老，日月如移越少年。
Missing var app=express()
Always prompts 404 error, stuck for a day, what's going on guys, please help, thank you! ! 
![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
Missing var app=express()