const restaurant = {
  name: 'Chicken Republic',
  openingHours: {
    thurs: {
      open: 12,
      close: 22,
    },
  },
};
const newRestaurant = { ...restaurant };
const newRestaurant2 = Object.assign({}, restaurant);

newRestaurant.name = 'Mega Chicken';
newRestaurant2.name = 'Mega chicken';

newRestaurant.openingHours.thurs.open = 8;
newRestaurant2.openingHours.thurs.open = 8;

console.log(restaurant); //{ name: 'Chicken Republic', openingHours: { thurs: { open: 8, close: 22 } }}

console.log(newRestaurant); //{name: 'Mega Chicken', openingHours: { thurs: { open: 8, close: 22 } } }

console.log(newRestaurant2); //{name: 'Mega Chicken',  openingHours: { thurs: { open: 8, close: 22 } } }