Optional chaining '?.' javascript

 The optional chaining ?. syntax has three forms:

1. obj?.prop – returns obj.prop if obj exists, otherwise undefined.
2. obj?.[prop] – returns obj[prop] if obj exists, otherwise undefined.
3. obj.method?.() – calls obj.method() if obj.method exists, otherwise returns undefined.

let user = {}; // user has no address alert( user?.address?.street ); // undefined (no error)

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let userGuest = {}; userGuest.admin?.(); // nothing (no such method)

https://javascript.info/optional-chaining