How to get the customer's data on the frontend checkout page's client side (with JavaScript) using the «Magento_Customer/js/model/customer» object?

Context: How to get the customer’s data on the frontend checkout page’s client side (with JavaScript)?

How is it implemented?

The «Magento_Customer/js/model/customer» JavaScript object interface

Usage examples

Despite of its wide interface, the only isLoggedIn() method is used:

How is the isLoggedIn() method of the «Magento_Customer/js/model/customer» object implemented and used?

See also: