Structs in Javascript

The only difference between object literals and constructed objects are the properties inherited from the prototype.

var o = {
  'a': 3, 'b': 4,
  'doStuff': function() {
    alert(this.a + this.b);
  }
};
o.doStuff(); // displays: 7

You could make a struct factory.

function makeStruct(names) {
  var names = names.split(' ');
  var count = names.length;
  function constructor() {
    for (var i = 0; i < count; i++) {
      this[names[i]] = arguments[i];
    }
  }
  return constructor;
}

var Item = makeStruct("id speaker country");
var row = new Item(1, 'john', 'au');
alert(row.speaker); // displays: john

I always use object literals

{id: 1, speaker:"john", country: "au"}

Following Markus's answer, in newer versions of JS (ES6 I think) you can create a 'struct' factory more simply using Arrow Functions and Rest Parameter like so:

const Struct = (...keys) => ((...v) => keys.reduce((o, k, i) => {o[k] = v[i]; return o} , {}))
const Item = Struct('id', 'speaker', 'country')
var myItems = [
    Item(1, 'john', 'au'),
    Item(2, 'mary', 'us')
];

console.log(myItems);
console.log(myItems[0].id);
console.log(myItems[0].speaker);
console.log(myItems[0].country);

The result of running this is:

[ { id: 1, speaker: 'john', country: 'au' },
  { id: 2, speaker: 'mary', country: 'us' } ]
1
john
au

You can make it look similar to Python's namedtuple:

const NamedStruct = (name, ...keys) => ((...v) => keys.reduce((o, k, i) => {o[k] = v[i]; return o} , {_name: name}))
const Item = NamedStruct('Item', 'id', 'speaker', 'country')
var myItems = [
    Item(1, 'john', 'au'),
    Item(2, 'mary', 'us')
];

console.log(myItems);
console.log(myItems[0].id);
console.log(myItems[0].speaker);
console.log(myItems[0].country);

And the results:

[ { _name: 'Item', id: 1, speaker: 'john', country: 'au' },
  { _name: 'Item', id: 2, speaker: 'mary', country: 'us' } ]
1
john
au

I use objects JSON style for dumb structs (no member functions).

It's more work to set up, but if maintainability beats one-time effort then this may be your case.

/**
 * @class
 */
class Reference {

    /**
     * @constructs Reference
     * @param {Object} p The properties.
     * @param {String} p.class The class name.
     * @param {String} p.field The field name.
     */
    constructor(p={}) {
        this.class = p.class;
        this.field = p.field;
    }
}

Advantages:

• not bound to argument order
• easily extendable
• type script support:

This is an old problem that it doesn't seem has been addressed yet. For what it's worth, I use immutability to get similar behavior. Using Typescript:

export class Point {
   public readonly X: number;
   public readonly Y: number;

   constructor(x: number, y: number)
   {
       this.X = x;
       this.Y = y;
   }

   public static SetX(value: number) : Point {
       return new Point(value, this.Y);
   }

   public static SetY(value: number) : Point {
       return new Point(this.X, value);
   }
}

This gets you a key benefit of a complex value type, namely that you can't accidentally modify the object via a reference to it.

The drawback of course is that if you DO want to modify a member you have to make a new instance, hence the static SetX and SetY functions.

It's a lot of syntactic sugar but I think it's worth it for special cases, like Point, that could potentially get used A LOT and lead to A LOT of bugs if values are changed accidentally.