小编Imt*_*mad的帖子

为什么我的数组没有重新渲染？

import React, { useEffect, useState } from 'react';

const App = () => {
    const [arr,setArr] = useState([5,4,3,2,1]);
    const handleClick = ()=>{
        let newArr = arr;
        newArr[0]++;
        setArr(newArr);
    };

    return (
        <>
            {arr.map((item) => (
                <h1 key={item}>{item}</h1>
            ))}
            <button onClick={handleClick}>buttong</button>
        </>
    );
}

export default App;