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Similar to a question I had some time back: Private properties in JavaScript ES6 classes

This question has more to do with the emergence of using WeakMaps and Symbols to store private variables. Since I would be declaring any private member structures at the top of the file, wouldn't this require a function closure around all of it? 

const _color = Symbol('color');
class colorPicker {
  constructor(color) {
    this[_color] = color;
  }
}

The _color is now gonna be in the window namespace, even if not hoisted. Is this proper ? or should the IIFE be wrapped around it?

Seems like ECMA may have missed something with this? Or do they intend to actually use private and public reserved keywords in ESNext?

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webdevinci
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  • Maybe [`Symbol.for()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol/for) is what you're looking for? That creates a symbol if not extant, or gets a symbol if already created, at a runtime level. Obviously, since it's runtime scoped, you'll probably want to use a longer string than 'color'... – Heretic Monkey Jul 05 '16 at 21:57
  • They will be module-scoped, so there is no reason to create another scopes with either IIFE or a `{ ... }` block. "The _color is now gonna be in the window namespace, even if not hoisted" --- why do you think so? – zerkms Jul 05 '16 at 22:47
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    Symbols are not private. – Bergi Jul 06 '16 at 00:05
  • @zerkms : I guess I didn't think about const / let not getting hoisted to the window namespace. I believe that is the answer I am looking for: **If the Symbol or WeakMap used for private variables is stored in a const/let, it won't get attached as a window property, even when not in a closure/block.** – webdevinci Jul 06 '16 at 15:17
  • @Bergi : The Symbol itself isn't private, but it looks like the contents of it are. – webdevinci Jul 06 '16 at 15:17
  • @webdevinci: No, everybody can access any symbol properties of an object he is holding. – Bergi Jul 06 '16 at 15:36

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