Returning __lldb_expr_ in front of instances of Struct & Class

I recently started getting “_lldb_expr” in front of every instance of struct and num. It happened even when I opened the already finished chapter files that I down loaded from this site. The expression is followed by a number that increases everytime I press run.

On page 291, initializing an instance of Car:
var c = Car(make: "FORD", model: "Fusion", year: 2013)

Returns:
__lldb_expr_7.Car

When I press run again I get:
__lldb_expr_9.Car

What is this?