jeena/en.javascript.info
1
0
Fork 0
Code Issues Pull requests Projects Packages Wiki Activity Actions

Update article.md

Browse source
This commit is contained in:
Ilya Kantor 2020-10-20 11:27:04 +03:00 • committed by GitHub
parent fca113b532
commit d961910b6c
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
1 changed files with 5 additions and 1 deletions
Download patch file Download diff file Expand all files Collapse all files

6
1-js/04-object-basics/07-optional-chaining/article.md
View file

@ -74,10 +74,14 @@ That's why the optional chaining `?.` was added to the language. To solve this p
## Optional chaining
The optional chaining `?.` stops the evaluation and returns `undefined` if the part before `?.` is `undefined` or `null`.
The optional chaining `?.` stops the evaluation if the part before `?.` is `undefined` or `null` and returns that part.
**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`:
- returns `value.prop` if `value` exists (just like `value.prop`),
- otherwise (when `value` is `undefined/null`) it returns that `value`.
Here's the safe way to access `user.address.street` using `?.`:
```js run