This project was bootstrapped with Create React App.
In the project directory, you can run:
Runs the app in the development mode.
Open http://localhost:3000 to view it in the browser.
The page will reload if you make edits.
You will also see any lint errors in the console.
Launches the test runner in the interactive watch mode.
See the section about running tests for more information.
Builds the app for production to the build folder.
It correctly bundles React in production mode and optimizes the build for the best performance.
The build is minified and the filenames include the hashes.
Your app is ready to be deployed!
See the section about deployment for more information.
Note: this is a one-way operation. Once you eject, you can’t go back!
If you aren’t satisfied with the build tool and configuration choices, you can eject at any time. This command will remove the single build dependency from your project.
Instead, it will copy all the configuration files and the transitive dependencies (Webpack, Babel, ESLint, etc) right into your project so you have full control over them. All of the commands except eject will still work, but they will point to the copied scripts so you can tweak them. At this point you’re on your own.
You don’t have to ever use eject. The curated feature set is suitable for small and middle deployments, and you shouldn’t feel obligated to use this feature. However we understand that this tool wouldn’t be useful if you couldn’t customize it when you are ready for it.
You can learn more in the Create React App documentation.
To learn React, check out the React documentation.
This section has moved here: https://facebook.github.io/create-react-app/docs/code-splitting
This section has moved here: https://facebook.github.io/create-react-app/docs/analyzing-the-bundle-size
This section has moved here: https://facebook.github.io/create-react-app/docs/making-a-progressive-web-app
This section has moved here: https://facebook.github.io/create-react-app/docs/advanced-configuration
This section has moved here: https://facebook.github.io/create-react-app/docs/deployment
This section has moved here: https://facebook.github.io/create-react-app/docs/troubleshooting#npm-run-build-fails-to-minify
虚拟DOM就是JS对象，用来描述真实的DOM；虚拟DOM之所以能提高性能，是因为JS中比较JS对象相对于比较真实DOM来说，不怎么耗性能。
React虚拟DOM的diff算法，建立在state发生改变时（即setState方法被调用，而且多次调用因为setState异步函数的关系进化为一次调用）调用，特征之一是同级比较逐层匹配。不仅如此，通过key值判断节点进行比较可以使得原节点和现节点建立关系，提高性能，且key值必须稳定，这也是为什么在项目中能不使用index作为key值就不要利用index作为key值的原因。
生命周期函数指在某一时刻组件会自动调用执行的函数
由于一些个人原因，暂时停止更新。
组件的生命周期可分成三个状态：
Mounting：已插入真实 DOM Updating：正在被重新渲染 Unmounting：已移出真实 DOM 生命周期的方法有：
componentWillMount 在渲染前调用,在客户端也在服务端。
componentDidMount : 在第一次渲染后调用，只在客户端。之后组件已经生成了对应的DOM结构，可以通过this.getDOMNode()来进行访问。 如果你想和其他JavaScript框架一起使用，可以在这个方法中调用setTimeout, setInterval或者发送AJAX请求等操作(防止异步操作阻塞UI)。
componentWillReceiveProps 在组件接收到一个新的 prop (更新后)时被调用。这个方法在初始化render时不会被调用。
shouldComponentUpdate 返回一个布尔值。在组件接收到新的props或者state时被调用。在初始化时或者使用forceUpdate时不被调用。 可以在你确认不需要更新组件时使用。
componentWillUpdate在组件接收到新的props或者state但还没有render时被调用。在初始化时不会被调用。
componentDidUpdate 在组件完成更新后立即调用。在初始化时不会被调用。
componentWillUnmount在组件从 DOM 中移除之前立刻被调用。