gretting.js

const form = document.querySelector(".js-form"),
  input = form.querySelector("input"),
  greeting = document.querySelector(".js-grettings");

const USER_LS = "currentUser",
  SHOWING_CN = "showing";

function saveName(text) {
  //사용자를 기억
  localStorage.setItem(USER_LS, text);
}
function handleSubmit() {
  //form형식을 제출할때 event
  event.preventDefault();
  const currentValue = input.value;
  paintGreeting(currentValue);
  saveName(currentValue);
}
function askForName() {
  //사용자입력 받기
  form.classList.add(SHOWING_CN);
  form.addEventListener("submit", handleSubmit);
}
function paintGreeting(text) {
  //화면에 표시
  form.classList.remove(SHOWING_CN);
  greeting.classList.add(SHOWING_CN);
  greeting.innerText = `Hello ${text}`;
}

function loadName() {
  //사용자가 있는지 없는지
  const currentUser = localStorage.getItem(USER_LS);
  if (currentUser == null) {
    askForName();
  } else {
    paintGreeting(currentUser);
  }
}

function init() {
  loadName();
}

init();