Setters are no longer called when setting properties in object initializers: what does this mean?

javascript

Solution

I think this refers to the issue of JSON hijacking. Have a look at

- Is it possible to do 'JSON hijacking' on modern browser?

- http://incompleteness.me/blog/2007/03/05/json-is-not-as-safe-as-people-think-it-is/

- http://haacked.com/archive/2008/11/20/anatomy-of-a-subtle-json-vulnerability.aspx, http://haacked.com/archive/2009/06/25/json-hijacking.aspx

- http://hackademix.net/2009/01/13/you-dont-know-what-my-twitter-leaks/

To repost my answer from this deleted question:

According to the specification, neither Array (EcmaScript 5.1 §11.1.4) nor Object literals (EcmaScript 5.1 §11.1.5) should be hijackable:

- They call "the standard built-in constructor with that name", not what you might have overwritten at `window.Array` or `window.Object`

- They use [[defineOwnProperty]], which does absolutely not take care of any setters on `Object.prototype`.

Nowadays, this should not be an issue any more in ES 5.1-compliant browsers.

Problem

On this JS MDN page it says this: JavaScript 1.8.1 note Starting in JavaScript 1.8.1, setters are no longer called when setting properties in object and array initializers. I just can't figure out what this is trying to tell me.

Original source

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