jQuery serialize 폼 인코딩

let formStr = $("form[name=mypage_form]").serialize();
// => name=홍길동&phone=...&id=...

let formArr = $("form[name=mypage_form]").serializeArray();
let formData = new FormData();
formArr.forEach(function (data) {
  formData.append(data.name, data.value);
});
if ($('input[name=file]')[0].files[0]) {
  formData.append('file', $('input[name=file]')[0].files[0]);
}
formData.append("flag", "member_modify");

• type=file은 serialize에 미포함 → FormData로 별도 append