What's the error in the code . Line 51:8: Parsing error: Unexpected token, expected "{"

Question

我正在学习 reactjs，但在最后一行 export App3 中遇到解析错误；请通过下面的代码人员让我知道错误是什么（代码中的错误是什么。第 51:8 行：解析错误：意外标记，预期为“{”）

import React, { Component } from "react";
import Student from "./Student";
import useCustomHook from "./Customhook";

export default class App extends Component {
  constructor(props) {
    super(props);

    console.log("App - Constructor Called");
    console.log(props.name);
    this.state = {
      roll: "101",
    };
  }
  static getDerivedStateFromProps(props, state) {
    console.log("app2");
    console.log(props, state);
    return null;
  }

  componentDidMount() {
    // you can get data from server and set the data to state
    // Ajax is also called in component did mount method
    console.log("app - Component did mount working properly");
  }

  render() {
    console.log("app rendered");
    return (
      <div>
        <Student name="Abhishek" />
        {/* <h1>Hello</h1> */}
      </div>
    );
  }
}

function App3() {
  const data = useCustomHook();

  return (
    <>
      <h1> Hello {data.currState}</h1>
      <button type="button" onClick={data.customHandleIncrement}>
        Increment
      </button>
    </>
  );
};

export  App3;

Answer 1

您必须使用语法 where use export before function App3()。像这样：

export function App3() {

或者您可以使用以下语法：

export { App3 };

What's the error in the code . Line 51:8: Parsing error: Unexpected token, expected "{"

What's the error in the code . Line 51:8: Parsing error: Unexpected token, expected "{"

user-interface

reactjs

reactjs-testutils

mern

react-fullstack