Chapter 3. Using Collections and Cocoa Data Types

Once I got past the basic Hello World beginner applications, I quickly began to realize the shortcomings of variables, especially with the Mad Libs (http://en.wikipedia.org/wiki/Mad_Libs) style applications that I was starting to write. These applications requested that the user enter in numerous strings and I was creating a separate variable for each input field that the user entered. Having all of these separate variables quickly became very cumbersome. I remember talking to a friend about this and he asked me why I was not using arrays. At the time, I was not familiar with arrays, so I asked him to show me what they were. Even though he had a TI-99/4A and I had a Commodore Vic-20, the concept of arrays was the same. Even today, the arrays found in modern development languages have the same basic concepts as the arrays I used on my Commodore Vic-20. While it is definitely possible to create a useful application without using collections, when used right, collections do make application development significantly easier.

In this chapter, we will cover the following topics:

• What is an array in Swift and how to use it?
• What is a dictionary in Swift and how to use it?
• What is a tuple in Swift and how to use it?
• How to use Cocoa data types in Swift?
• How to use Foundation data types in Swift?