iOS 11 Developer Course Tutorial - Swift Playgrounds Part 9 Video Lecture

now that you've built your first cat
ears app and you're reasonably familiar
with how Xcode works and what Swift is
in this section we're going to be diving
deep into the Swift language and
learning in detail all of the things
that we've looked at so far like
variables types if statements and a lot
lot more to allow us to go on and build
big powerful apps one feature in Xcode
that I use quite a lot when I'm just
playing around with code and it's very
useful to see the results of your code
immediately is playgrounds and this is
what we're going to be using in this
section so an Xcode go to file new
playground and we'll start off with a
blank iOS playground save it wherever
you like I'll put mine on the desktop
and here we go so this is what
playgrounds look like it's extremely
simple and essentially we just have a
simple script like we're used to seeing
in our view controller dot Swift file
but without any of the faff there's no
view controllers
there's no viewdidload method or did
receive memory warning
there's just our code and even more
usefully you can see the results of that
code immediately you don't have to press
play every time and wait five to ten
seconds for your app to run before you
see what the code actually does so it's
really great for testing things out and
learning the basics of the Swift
language so here's a very quick
challenge can you print your name to the
logs or to the console go for it
hopefully you manage that we learned how
to do that in the previous section
it's just print and then parenthesis and
then in speech marks your name there we
go and it should be pretty quick you can
see there we go in the the log section
down here also known as the console
we've got my name
we can also see the value of a variable
that's been created or something that's
been printed to the console here on the
right of the playground you'll notice it
has a backslash n that short for newline
and that's just to indicate that it's
printed Rob but it's also a kind of
invisible newline there so if for
example I print hello that will print on
a new line so that backslash n just
indicates that it's printed a new line
as well as whatever you've told it to
print okay so that's how playgrounds
work they're just a way that you can
write lines of code and have them
process immediately and see the results
straight away so let's dive right in and
use our playground to see how variables
work in Swift