JS private 如何使用

[kaiwei]

最近看了道爷的 2001 文章
http://www.crockford.com/javascript/private.html
在自己的机器上跑，并没有 private 的效果啊。
```javascript
function Container(param) {
this.member = param;
var secret = 3;
var that = this;
}
var myContainer = new Container('abc');
console.log(myContainer.member); // 依然会打印 abc
myContainer.member = 'efg';
console.log(myContainer.member); // 会打印 efg
```
求解。多谢！

[Septembers]

see https://www.web-tinker.com/article/20833.html
see https://www.web-tinker.com/article/20742.html
see https://mdn.io/Symbol
see https://mdn.io/getOwnPropertySymbols
see https://mdn.io/WeakMap

[Septembers]

您认真看您发的文章了吗？ secret 才是私有的啊

[kaiwei]

@Septembers 在 Private 那个标题下面：
This constructor makes three private instance variables: param, secret, and that. They are attached to the object, but they are not accessible to the outside, nor are they accessible to the object's own public methods. They are accessible to private methods. Private methods are inner functions of the constructor.
他说，三个都是不能 accessible to the outside 。

[xcodebuild]

@kaiwei 你访问的是 member ，不是这三个的任何一个，有任何问题么？

[yuriko]

原谅我放荡不羁的笑点……

[jsonline]

为什么要把其它语言的概念搬到 JS

[jkeylu]

ES6 中 closure + Symbol 就能实现 private 的效果

[neoblackcap]

@kaiwei 如 @codefalling 所说你访问的是 member ，原文只说 param, secret, that 三个变量是私有的而已

[xuzicn]

额外插一句， JS 没有 private 这一说，想要实现数据保护经常引入额外的麻烦