react redux是什么？

npm install --save react-redux

yarn add react-redux

import React from "react";
import ReactDOM from "react-dom";
import { Provider } from "react-redux";
import store from "./store";
import App from "./App";
const rootElement = document.getElementById("root");
ReactDOM.render(
  <Provider store={store}>
    <App />
  </Provider>,
  rootElement
);

import { connect } from "react-redux";
import { increment, decrement, reset } from "./actionCreators";
// const Counter = ...
const mapStateToProps = (state /*, ownProps*/) => {
  return {
    counter: state.counter
  };
};
const mapDispatchToProps = { increment, decrement, reset };
export default connect(
  mapStateToProps,
  mapDispatchToProps
)(Counter);