scala语法学习

https://www.runoob.com/scala/scala-install.html

https://www.shuzhiduo.com/A/GBJrLp6ad0/

https://blog.csdn.net/shenlei19911210/article/details/78538255

https://twitter.github.io/scala_school/zh_cn/basics2.html

https://www.cnblogs.com/barrywxx/p/10850502.html