const Statuses = Object.freeze({

  UNKNOWN : 0,

  OK      : 1,

  ERROR   : 2,

  STOPPED : 3

});

​

class myStatus extends Object{

  constructor() {

    super();

    this.status_id = Statuses.UNKNOWN;

  }

​

  valueOf(){

    return this.status_id;

  }

  getStatus(){

    return this.status_id;

  }

}

​

var a = new myStatus();

a.status_id = Statuses.ERROR;

console.log(a == Statuses.ERROR);

console.log(a.getStatus() === Statuses.ERROR);

console.log(a.valueOf() === Statuses.ERROR); //Isn't this the same as the line bellow?

​

​

console.log(typeof(Statuses.ERROR));

console.log(typeof(a) );

​

console.log(a.valueOf() === Statuses.ERROR); //Why is this false but the rest are true?

​