useEffect Hook to Check User Details in Local Storage

If user token is in [Local Storage], save user details to state and to blogService.

useEffect(() => {
  const loggedUserJSON = window.localStorage.getItem('loggedBlogListAppUser')
  if (loggedUserJSON) {
    const user = JSON.parse(loggedUserJSON)
    setUser(user)
    blogService.setToken(user.token)
  }
}, [])

Note -> empty array as the parameter of effect ensures the effect is executed only when the component rendered for the first time

Source -> Using the Effect Hook