Kotlin入门

introduction

flow control

functions

oop

ref

https://www.kotlincn.net/docs/reference/

null https://www.jianshu.com/p/79c1828b6cf7

https://www.jianshu.com/p/8679ab2569e8

https://www.programiz.com/kotlin-programming/hello-world

https://www.jianshu.com/p/79c1828b6cf7