state: {
  users: [{name: 'Oscar', age: 23}, {name: 'Jens', age: 23}, {name: 'Olof', age: 25}]
}

// Vuex mutation
// Vue uses dependency tracking via Object.defineProperty
// so that components which are dependant on the state are automatically re-rendered.
// No need for shouldComponentUpdate, immutability or full component vdom diffing
incrementFirstAge(state) {
  // mutate state
  users[0].age++
}

// Redux reducer
// State has to be immutable for React & the default shouldComponentUpdate to trigger.
// It is equally or more expensive the "Vue way" and hands more responsibility to the developer
// which has been abstracted & taken care of in the Vue case.
incrementFirstAge(state) {
  // create state
  return {
    users: [
      ...state.users,
      {
        ...state.users[0],
        age: state.users[0].age + 1
      }
    ]
  }

  // alt. use something like Immutable but then it's still more "code" for the developer
  // to write and another, quite large, library to master.
}