hook-example.jsx

function Profile ({userId}) {
    const [profile, setProfile] = useState(null)
    useEffect(() => {
        fetch(`/api/users/${userId}`)
        .then(res => {
            setProfile(res.json().profile)
        })
    }, [userId]) // run when it has new userId
    return (
        <div>{profile && profile.full_name}</div>
    )
}