Merge using Object assign

object_assign.js

const user = {
  name: 'David',
  phone: 122345678,
  location: {
    city: 'Camden',
    country: 'UK'
  }
};
const updates = {
  name: 'David',
  phone: 123456789,
  location: {
    city: 'Smithfield'
  }
};
console.log(Object.assign({}, user, updates));
/* output:
{ 
  name: 'David',
  phone: 123456789,
  location: {
    city: 'Smithfield'
  }
}
*/