I think the following is equivalent to the safe navigation operator, although a bit longer:

var streetName = user && user.address && user.address.street;

streetName will then be either the street name or null/undefined.

If you want it to default to something else you can combine with the above shortcut or to give:

var streetName = (user && user.address && user.address.street) || "Unknown Street";

I think the following is equivalent to the safe navigation operator, although a bit longer:

var streetName = user && user.address && user.address.street;

streetName will then be either the value of user.address.street or undefined.

If you want it to default to something else you can combine with the above shortcut or to give:

var streetName = (user && user.address && user.address.street) || "Unknown Street";