"useRefs“变量是div引用的初始值吗？

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

function MyComponent() {
  const myRef = useRef();

  useEffect(() => {
    console.log(myRef.current); // 访问DOM元素
  }, []);

  return <div ref={myRef}>Hello World</div>;
}

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

function MyComponent() {
  const myComponentRef = useRef();

  useEffect(() => {
    console.log(myComponentRef.current); // 访问组件实例
  }, []);

  return <ChildComponent ref={myComponentRef} />;
}

const ChildComponent = React.forwardRef((props, ref) => {
  // 子组件逻辑
});

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

function MyComponent() {
  const countRef = useRef(0);
  const increment = () => {
    countRef.current += 1;
    console.log(countRef.current); // 访问变量
  };

  useEffect(() => {
    increment();
  }, []);

  return <button onClick={increment}>Increment</button>;
}