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Update article.md to expand on property order in objects #3368

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9b28c13
Clarify property order
jvilders Feb 11, 2023
8ddbe68
Change object name in example
jvilders Feb 11, 2023
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17 changes: 16 additions & 1 deletion 1-js/04-object-basics/01-object/article.md
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Expand Up @@ -392,7 +392,7 @@ Also, we could use another variable name here instead of `key`. For instance, `"

Are objects ordered? In other words, if we loop over an object, do we get all properties in the same order they were added? Can we rely on this?

The short answer is: "ordered in a special fashion": integer properties are sorted, others appear in creation order. The details follow.
The short answer is: "ordered in a special fashion": Integer properties appear first in sorted order, then other properties appear in creation order. The details follow.

As an example, let's consider an object with the phone codes:

Expand Down Expand Up @@ -472,6 +472,21 @@ for (let code in codes) {

Now it works as intended.

If an object has both integer properties and non-integer properties, the integer properties will appear first, regardless of creation order.

```js run
let favoriteGamesTopThree = {};
favoriteGamesTopThree.year = 1996;
favoriteGamesTopThree.author = "John Smith";
favoriteGamesTopThree[3] = "Crash Bandicoot";
favoriteGamesTopThree[2] = "Super Mario 64";
favoriteGamesTopThree[1] = "Quake";

for (let prop in favoriteGamesTopThree) {
alert( prop ); // 1, 2, 3, year, author
}
```

## Summary

Objects are associative arrays with several special features.
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