In JS for-in loop enumerates keys in the insert order. So {x,y,z} is different f... | Hacker News

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		_0w8t on July 31, 2018 \| parent \| context \| favorite \| on: Why the New V8 Is So Damn Fast In JS for-in loop enumerates keys in the insert order. So {x,y,z} is different from {z,x,y}

mort96 on July 31, 2018 [–]

AFAIK, that's not true; the spec doesn't guarantee that it iterates in insertion order, it's just how it's commonly implemented in browsers.

topaxi on July 31, 2018 | [–]

Nope, they should be iterated in their defined order: https://tc39.github.io/ecma262/#sec-ordinaryownpropertykeys

I think they added this with ES2015.

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