setValue的值，監(jiān)聽的是num的值，為什么useCallBack里輸出兩遍
import React, { useCallback, useEffect, useLayoutEffect, useMemo, useState} from "react";
let set = new Set()
function StateFunction() {
? ? const [value, setValue] = useState(100)
? ? const [num, setNum] = useState(1)
? ?const getNumberCallBack = useCallback(function() {
? ? ? ? console.log('num值不變===', num, num*2) ?// 輸出了兩遍
? ? ? ? return num * 2
? ? }, [num])
? ? set.add(getNumberCallBack)
? ? console.log('set=====', set.size, set)
? ? return <div onClick={() => setValue(value + 1)}>
? ? ? ? 這是一個(gè)函數(shù)組件----
? ? ? ? {'getNumberCallBack====' + getNumberCallBack()}
? ? </div>
