What does "?" mean? in the user?.name entry (question to question ->)?

Question

JavaScript

I saw this code in the manual:

@Component({
    selector: 'my-app',
    template: `<div>
                    <p>Имя пользователя: {{user?.name}}</p>
                    <p>Возраст пользователя: {{user?.age}}</p>
               </div>`,
    providers: [HttpService]
})

Actually it works, but what do these questions mean?

Answer 1

Alexander Belov 's answer is not accurate.
There is no check for the presence of name or age, it is checked if user != null, otherwise user cannot contain any parameters at all.
those. user?.name can be "decomposed" into user==null?'':user.name
without this, there will be an error:

user = null
user.name
VM111:1 Uncaught TypeError