When you launch Xcode it will ask you what you want to do, and l’d like you to choose “Get Started with a Playground" - this is a sandbox where you can type Swift code and see immediate results.
The default is a blank playground for iOS, which is fine, So click Next then Create to save it on your desktop.
In this lesson I want to introduce you to variables, which are places where you can store program data. They are called variables because they can vary - you can change their values freely.
Playgrounds start with a line of code that creates a variable for us:
var str = "Hello, playground"
That creates a new variable called str, giving it the value Hello, playground. On the right of the playground you can see "Hello, playground" in the output area - that’s Xcode showing us the value was set.
Because str is a variable we can change it:
str = "Goodbye"
We don’t need var the second time because the variable has already been created — we’re just changing it.
Although Swift is pretty relaxed about how you name variables, it’s usually a good idea to make them descriptive.
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