react hooks setInterval,Why can it be modified for the first time

Why is it that the correct count value can be obtained in setinterval after the first click, and then the transformation does not occur again?

import React, { useEffect, useState } from 'react';  const Demo1 = () => {    let [count, setCount] = useState(1);    const onCountClick = () => {      count += 1;      setCount(count);    };    useEffect(() => {      setInterval(() => {        console.log(count);      }, 1000);    }, []);    console.log(count);    return <button onClick={() => onCountClick()}>test</button>;  };  

https://stackoverflow.com/questions/67444566/react-hooks-setinterval-why-can-it-be-modified-for-the-first-time May 08, 2021 at 02:04PM