What is the difference between using constructor vs getInitialState in React / React Native?

问题：

I've seen both used interchangeably.我见过两者交替使用。

What are the main use cases for both?两者的主要用例是什么？ Are there advantages / disadvantages?有没有优点/缺点？ Is one a better practice?一种更好的做法吗？

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解决方案：

参考一： https://en.stackoom.com/question/24gEQ
参考二： https://stackoom.com/question/24gEQ