React componentDidMount“解析错误：缺少分号”

Question

“解析错误：缺少分号”。

语法错误：client\src\App.js：缺少分号 (15:21)

此错误显示在 componentDidMount() 行上。

完整的代码如下。

import React, { Component } from "react";
import AppNavBar from "./components/AppNavbar";
import ShoppingList from "./components/ShoppingList";
import ItemModal from "./components/ItemModal";
import { Container } from "reactstrap";

import { Provider } from "react-redux";
import store from "./store";
import { loadUser } from "./actions/authActions";

import "bootstrap/dist/css/bootstrap.min.css";
import "./App.css";

function App() {
  componentDidMount() {
    store.dispatch(loadUser());
  }
  return (
    <Provider store={store}>
      <div className="App">
        <AppNavBar />
        <Container>
          <ItemModal />
          <ShoppingList />
        </Container>
      </div>
    </Provider>
  );
}

export default App;

Answer 1

导入使用效果：

import { useEffect } from "react";

...并替换：

componentDidMount() {
  store.dispatch(loadUser());
}

和：

useEffect(() => {
  store.dispatch(loadUser());
}, []);