4 ms·

Why does it have to be that the order of members matters? shouldn't both {x,y,z} and {z,x,y} compile down to {x,y,z}?

• fpoling 8y ago
  In JS for-in loop enumerates keys in the insert order. So {x,y,z} is different from {z,x,y}
  • mort96 8y ago
    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 8y ago
      Nope, they should be iterated in their defined order: https://tc39.github.io/ecma262/#sec-ordinaryownpropertykeys https://tc39.github.io/ecma262/#sec-ordinaryownpropertykeys I think they added this with ES2015.