Answers for "mount and unmount in useeffect"

useeffect will unmount

useEffect(() => {
    return () => {
      console.log("cleaning up --> unmount ");
    };
  }, []);

component unmount useeffect

useEffect( () => console.log("mount"), [] );
useEffect( () => console.log("will update data1"), [ data1 ] );
useEffect( () => console.log("will update any") );
useEffect( () => () => console.log("will update data1 or unmount"), [ data1 ] );
useEffect( () => () => console.log("unmount"), [] );