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Update "Property flags and descriptors" article #260

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Dec 24, 2022
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Update "Property flags and descriptors" article #260

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11 changes: 5 additions & 6 deletions 1-js/07-object-properties/01-property-descriptors/article.md
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Original file line number Diff line number Diff line change
Expand Up @@ -63,7 +63,7 @@ Object.defineProperty(obj, propertyName, descriptor)
```

`obj`, `propertyName`
: The object and property to work on.
: The object and its property to apply the descriptor.

`descriptor`
: Property descriptor object to apply.
Expand Down Expand Up @@ -116,14 +116,14 @@ Object.defineProperty(user, "name", {
});

*!*
user.name = "Pete"; // Error: Cannot assign to read only property 'name'...
user.name = "Pete"; // Error: Cannot assign to read only property 'name'
*/!*
```

Now no one can change the name of our user, unless they apply their own `defineProperty` to override ours.

```smart header="Errors appear only in strict mode"
In the non-strict mode, no errors occur when writing to non-writable properties and such. But the operation still won't succeed. Flag-violating actions are just silently ignored in non-strict.
In non-strict mode, no errors occur when writing to non-writable properties and such. But the operation still won't succeed. Flag-violating actions are just silently ignored in non-strict.
```

Here's the same example, but the property is created from scratch:
Expand All @@ -140,11 +140,10 @@ Object.defineProperty(user, "name", {
*/!*
});

alert(user.name); // Pete
user.name = "Alice"; // Error
alert(user.name); // John
user.name = "Pete"; // Error
```


## Non-enumerable

Now let's add a custom `toString` to `user`.
Expand Down