This evening I was given the opportunity to speak at Mobile DC to present on Playgrounds and the Swift programming language. I explained what Swift was and how Playgrounds can be used to help development in it. I provided a live-demo of using a Playground to make a UIView, then we created a fairly simple implementation of XKCD's <a>Geohashing</a>.

1. Playgrounds: A Swift
Introduction
Jeremy Curcio
MobileDC - 4/2/2015

2. Who Am I?
Software Developer from
Baltimore, Maryland
Works for Planit
Advertising
Writing iOS Apps since 2008
Hockey Player
Pokémon Player

3. Agenda
Overview of Swift
Learn a bit about Playgrounds
See what you can do in Playgrounds
Build a small app in Swift, utilizing
Playgrounds

4. What Is Swift?
New programming language developed by
Apple
Introduced at WWDC14
Works alone, or side-by-side with Objective-C
Powerful and Fast

5. Swift Quick Look
Variables
“let” vs “var”
Type Annotations
Swift infers type when possible

6. Swift Quick Look
Functions
Basic
With Parameters
With Return Value

7. What Are Playgrounds?
A File Wrapper
Contains Swift file
Resources
Timeline

8. What Playgrounds Aren’t
Where to write full app
How to test code on a device
A way to test code that requires user
interaction
A way to performance test your code

9. Why Use Playgrounds?
Great way to:
Learn
Explore
Visualize
Much quicker than creating a Project

10. How Do Playgrounds Work?
Code is on the left
Results are on the right
Every code change recompiles
Timelines show results in more detail

11. Features Of Playgrounds
Quick Look
Available for:
Colors
Strings
Images
Views
Arrays/Dictionaries
And many more…

12. Features Of Playgrounds
Timeline
Preview code as it’s written
View changes in real time
Scrub through codes execution in time

13. Playground vs Project
Playground
File -> New ->
Playground
Enter Name
Select Platform
Write Code
Project
Create Project
Choose Template
Save Project
Create Files
Write Code
Set Up Provisioning
Build
Run

14. Let’s Play?

15. Our Playground
What we did:
Used a for loop
Created and
modified a UIColor
variable
Created and
previewed a UIView
What we didn’t do:
Create an Xcode
Project
Never “built” the
code
So much more!

16. What Else Can Playgrounds Do?
XCPlayground
Custom Quick Looks
Quick Look you custom objects
Use Resources
API’s
Images
Asynchronous Code

17. Let’s Build Something
XKCD #426: Geohashing
“Saturday is game night.”

18. Let’s Build Something
Goal
Create a fully functioning app in Swift
Use a Playground to test as we go
Caveats
Storyboard pre-made
Project already set up
Code is pre-written/pre-tested

19. Let’s Build!

20. `

21. Resources
WWDC14 Session 408 - Swift Playgrounds
The Swift Programming Language - iBooks
Code/Slides available at www.jcurcio.com