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closes #2433

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Ilya Kantor 2021-01-13 19:53:38 +03:00
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1-js/04-object-basics/07-optional-chaining/article.md
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@ -74,12 +74,12 @@ That's why the optional chaining `?.` was added to the language. To solve this p
## Optional chaining
The optional chaining `?.` stops the evaluation if the part before `?.` is `undefined` or `null` and returns that part.
The optional chaining `?.` stops the evaluation if the value before `?.` is `undefined` or `null` and returns `undefined`.
**Further in this article, for brevity, we'll be saying that something "exists" if it's not `null` and not `undefined`.**
In other words, `value?.prop`:
- is the same as `value.prop` if `value` exists,
- works as `value.prop`, if `value` exists,
- otherwise (when `value` is `undefined/null`) it returns `undefined`.
Here's the safe way to access `user.address.street` using `?.`: