1.关键概念

1.CreateElement
2.render
3.Component
4.setState
5.JSX
6.虚拟dom
7.diff算法
8.redux

serState 是异步更新
Object.assign

tree diff 同级比较，非同级无优化
component diff
element diff div span
新的 inster 有的move复用，老的 remove