What is "?." when accessing object property in JS (typescript?) [duplicate]

Question

I have found this piece of code in on example:

const value: Token | undefined = object?.token

What this part "object?.token" actually means?

I cannot find it online, I am not sure how to search for it.

I understand that object.token is used to access token property of object, but what is the use of "?"

Thanks

Alireza Ahmadi · Accepted Answer · 2021-07-07 09:40:00Z

3

This is called Optional Chaining in Typescript.

Optional chaining lets us write code where TypeScript can immediately stop running some expressions if we run into a null or undefined.

For your example if object is not null and undefined get the value of property token.

answered Jul 7, 2021 at 9:40

Alireza Ahmadi

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