objects.js

const robot = {
  model: 'B-4MI',
  mobile: true,
  greeting() {
  	console.log(`I'm model ${this.model}, how may I be of service?`);
  }
}

const massProdRobot = (model, mobile) => {
  return {
    model,
    mobile,
    greeting() {
      console.log(`I'm model ${this.model}, how may I be of service?`);
    }
  }
}

const shinyNewRobot = massProdRobot('TrayHax', true)

const chargingStation = {
  _name: 'Electrons-R-Us',
  _robotCapacity: 120,
  _active: true,
  _chargingRooms: ['Low N Slow', 'Middle of the Road', 'In and Output'],

  set robotCapacity(newCapacity) {
    if (typeof newCapacity === 'number') {
      this._robotCapacity = newCapacity;
    } else {
      console.log(`Change ${newCapacity} to a number.`)
    }
  },
  get robotCapacity() {
    return this._robotCapacity;
  }
}

class User {

  constructor(name) {
    // invokes the setter
    this.name = name;
  }

  get name() {
    return this._name;
  }

  set name(value) {
    if (value.length < 4) {
      alert("Name is too short.");
      return;
    }
    this._name = value;
  }

}

let user = new User("John");
alert(user.name); // John

user = new User(""); // Name is too short.