Immutable Code

immutable.js

const user = {
  name: 'John Due',
  birthdate: '1988-08-15',
}

const changeName = (user, newName) => {
  return {
    ...user, // destructuring user object
    name: newName, // override name attribute with new name
  }
}

const userWithNewName = changeName(user, 'Jojo')
// the old user object has name = 'John Due' and the new object, name = 'Jojo'
console.log(user, userWithNewName)