React Hooks - 作为prop传递的函数组件内的函数无法访问状态

Question

I have read about React hooks and wanted to try it on this new website I have been developing. I am trying to pass an async function as a prop. Part of the function is to set my "cities" state and console log just to see if the API works. I have been receiving "setCities is not a function" error or, cities returns undefined if I just console log it directly. I think the function can't access the {cities, setCities} state. I have tried it in class component and it works. Has anyone encountered similar situations? Below is the code sample:

import React, { useState } from "react";
import axios from "axios";
import Menu from "./Menu";

function App() {
    const { cities, setCities } = useState([]);

    const searchSubmit = async term => {
        try {
            const res = await axios.get("http://localhost:8080/general/search", {
                params: { city: term }
            });
            setCities(res.data);
            console.log(cities);
        } catch (err) {
            console.log(err.message);
        }
    };

    return (
        <div className="ui container">
            <Menu handleSearchSubmit={searchSubmit} />
        </div>
    );
}

Answer 1

useStates return an array, not an object...

So you can change

const { cities, setCities } = useState([]);

to

const [ cities, setCities ] = useState([]);

And it should work.