What kind of empty Javascript Object is this?

Question

The object '0' expanded below with the property, date, is an object in its own, but the object is empty when expanded except for the proto object. What is the greyed out date about?? It doesnt look like the object's key, since "date" should be the key.

I'm trying to replicate this object and have no idea how or what's going on.

This is just the way Chrome displays a date inside an object in the developper console. Type `{ date: new Date() }` in your console and you'll see the same. — Serge K., Feb 20 '19 at 15:14
@SergeK. So why doesnt the object above do that? How can I convert the above date property to the one below? — ima_prog, Feb 20 '19 at 15:15
Because it isn't a date, but the string representation of a date. — Serge K., Feb 20 '19 at 15:16
@SergeK. Ok thanks. How do I convert the above string to a date property like the one below? — ima_prog, Feb 20 '19 at 15:17
that is just what you would get from the `.toString()` method. — Gabriele Petrioli, Feb 20 '19 at 15:17
https://stackoverflow.com/questions/5619202/converting-a-string-to-a-date-in-javascript/5619326 — Serge K., Feb 20 '19 at 15:17
Chrome decides on and off to show that date. Very strange behaviour — mplungjan, Feb 20 '19 at 15:20
@SergeK. So is date the key of the object and the actual value of the date the value of the object? Im just wondering why when u expand the object, that it's empty. — ima_prog, Feb 20 '19 at 15:29
You see `{}` at the end. This is telling: is an object. If you click on date, then you'll see the properties on it. — Bhojendra Rauniyar, Feb 20 '19 at 15:38
@BhojendraRauniyar the only properties inside if i click on the date arrow is the proto object. No further details on date show. — ima_prog, Feb 20 '19 at 15:39
@BhojendraRauniyar https://imgur.com/a/5jy3DWH i expanded the object, there is no property underneath except the proto object. I'm not sure when I did the toString method. — ima_prog, Feb 20 '19 at 15:44
@SergeK. https://imgur.com/a/5jy3DWH I expanded the object here. How come the date isnt listed as a property below like other objects in chrome? — ima_prog, Feb 20 '19 at 15:45

score 1 · Accepted Answer · answered Feb 20 '19 at 16:14

The greyed-out thing is part of the immediate representation of the Date object in the console - just like it is displaying Array(200) for your array.

You will get the same representation when doing console.dir as when having the object as a property of another object.

You will get a different representation when doing console.log, as that shows different things depending on the type of the logged value and not always the expansible object representation.

the object is empty when expanded except for the proto object.

Yes, Date instances don't have any own properties. The timestamp value is stored in an internal property which is not shown by the devtools.

What kind of empty Javascript Object is this?

1 Answers1