optional chaining in javascript

Imaging if you need to access deep level of property and you are not sure that if such properties exists deep down, you are doing something like

books && books.book && books.book.authors && books.book.authors.author

This is really difficult to read and understand sometime. there is something called optional chaining in javascript proposal which you can use if you include in babel-plugin-proposal-optional-chaining to your babebl.

The sytax is really easy using

?.

books?.book?.authors?.author

all you need is chain the child properties, now everything is so much easier to read.