Errata

I'm using Swift 3.0. So far I haven't run into much code in your text that requires substantial modification, and I'm finding the text very helpful in learning Swift (or I think I am ... we'll see if I can actually do anything useful with it).

However, in the Chapter 3 example under "Initialization and Deinitialization", your code has:

var example : InitAndDeinitExample?

// using the designated initializer
example = InitAndDeinitExample() // prints "I've been created!"
example = nil // prints "I'm going away"

I think the destructor is incorrect: setting example to be nil doesn't invoke the deinit procedure. In fact, the message that should be emitted by deinit() isn't printed (and it appears that the procedure isn't invoked). The message *is* emitted as Playground reaches the end of the code body -- presumably because on exiting the system deallocates anything left around.

And oddly enough, removing "example = nil" and invoking the deinit with
example.deinit()
causes a Playground crash. (!)

1) Am I right that setting example to nil doesn't actually destroy the "example" object?
2) What's the right way to deallocate the object?

the code
return "A \(self.color) vehicle"
in the playground outputs
"A Optional("Red") vehicle"
if one adds the ! to the optional var color
return "A \(self.color!) vehicle"
the output is as displayed in the book
"A Red vehicle"

the code inside class Vehicle
print("Traveling at \(maxSpeed) kph")
in the playground when called by the code
redVehicle.travel()
displays a result of
Vehicle
instead of the published result of the print of
"Traveling at 90 kph"

What is the correct code for the playground to print what you say it should print?

in the playground
example = InitAndDeinitExample() // prints "I've been created!"
displays
InitAndDeinitExample

and
example = nil // prints "I'm going away"
displays
nil

and
example = InitAndDeinitExample(text: "Hello")
displays
InitAndDeinitExample

how does one try the sample code and get the results published in the book?