认识

一、认识

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**useLatest**返回当前最新值的 Hook，可以避免闭包问题。

二、语法

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const latestValueRef = useLatest<T>(value: T): MutableRefObject<T>;

三、场景

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3.1 在 useEffect 闭包中获取最新状态

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

export default () => {
  const [count, setCount] = useState(0);

  const latestCountRef = useLatest(count);

  useEffect(() => {
    const interval = setInterval(() => {
      setCount(latestCountRef.current + 1);
    }, 1000);
    return () => clearInterval(interval);
  }, []);

  return (
    <>
      <p>count: {count}</p>
    </>
  );
};