The safe navigation operator(?)(or known as Elvis Operator) is used to guard against null
and undefined
values in property paths when you are not aware whether a path exists or not. i.e. It returns value of the object path if it exists, else it returns the null value.
For example, you can access nested properties of a user profile easily without null reference errors as below,
<p>The user firstName is: {{user?.fullName.firstName}}</p>
Using this safe navigation operator, Angular framework stops evaluating the expression when it hits the first null value and renders the view without any errors.