https://www.jianshu.com/p/7716dc8b2206 Flow and use basic grammar
https://www.cnblogs.com/tianxiangbing/p/flow.html used to regulate the flow of variable types javascript
https://www.jianshu.com/p/7716dc8b2206 Flow and use basic grammar
https://www.cnblogs.com/tianxiangbing/p/flow.html used to regulate the flow of variable types javascript