backwardform.js

function* formGen() {
  let name, surename, date;

  nameLabel: 
  while (true) {
    name = yield('Enter name');
    if (name === 'cancel') return;

    surenameLabel:
    while (true) {
      surename = yield('Enter surename');
      if (surename === 'back') continue nameLabel;

      dateLabel: 
      while (true) {
        date = yield('Enter date');
        if (date === 'back') continue surenameLabel;
        break nameLabel;
      }
    }
  }
  return { name, surename, date };
}

const form = formGen();

const question = form.next(); //Enter your name
const question2 = form.next('Anton'); //Enter your surename
const question3 = form.next('Lo'); // Enter your birthdate 
const backQuestion = form.next('back'); // Enter your surename
const dateQuestion = form.next('Lopan');
const formData = form.next('01.01.01');


console.log(formData) // Anton Lopan 01.01.01