如何正确访问Java类的属性

Question

I have this class definition:

$.note = function() {}
$.note.prototype = {
  init: function(note) {
    this.note = note;
    this.ctrl = document.getElementById(note);
  },
  // I have these getter functions because I was getting errors using
  // myObject.note or myObject.ctrl
  getNote: function() {
    return this.note;
  },
  getCtrl: function() {
    return this.ctrl;
  }
}

I created a new object with this class like this:

var note = new $.note('C');

Which I can access in my console like this:

But when I try and access note.getNote(), I get undefined as the response:

Am I going about accessing these properties incorrectly? I've tried using just note.note or note.ctrl, and I get the same thing...

Answer 1

Nothing's going to call that "init" function if you don't.

$.note = function(note) { this.init(note); }

Some frameworks provide an object system that uses constructor helper functions like that, but plain JavaScript doesn't.

Answer 2

Try this:

$.note = function(note) { this.note = note;}

or you should call init function:

var note = new $.note();
note.init('C');