Person constructor

"use strict";

function Person(name, middlename, lastname) {
  this.name = ""
  this.middlename = ""
  this.lastname = ""

  Object.defineProperties(this, {
    name: {
      get: function() {
        return name;
      },
      set: function(value) {
        if (!/^\w+$/.test(value))
          throw new Error(`name must contain only word characters`)
        name = value;
      }
    },
    middlename: {
      get: function() {
        return middlename;
      },
      set: function(value) {
        if (!/^\w+$/.test(value))
          throw new Error(`middlename must contain only word characters`)
        middlename = value;
      }
    },
    lastname: {
      get: function() {
        return lastname;
      },
      set: function(value) {
        if (!/^\w+$/.test(value))
          throw new Error(`lastname must contain only word characters`)
        lastname = value;
      }
    },
  });

  this.name = name;
  this.middlename = middlename;
  this.lastname = lastname;
}

Person.prototype.toString = function() {
  return `${this.name} ${this.middlename} ${this.lastname}`;
}

function main() {
  let p = new Person("A", "B", "C");
  console.log(p.toString());
  p.name = "D";
  console.log(p.name);
}