Order of iterating Javascript object properties? [duplicate]

Question

If I have this code :

o["a"]=1;
o["b"]=1;
o["c"]=1;
o["d"]=1;


for (var k in o)
{
  alert(k)
}

Would it always(cross browser) be alerted in the same order as the attribute were added ?
And what about this ? (same question)

var o={a:1,b:1,c:1,d:1} ?

James Allardice · Accepted Answer · 2013-04-12 09:24:28Z

2

No. The order is not specified. From the spec:

The mechanics and order of enumerating the properties ... is not specified.

answered Apr 12, 2013 at 9:24

James Allardice

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