NEW: Subscribe to Hacking with Swift+ and accelerate your learning! >>

Strings and integers

Swift is what’s known as a type-safe language, which means that every variable must be of one specific type. The str variable that Xcode created for us holds a string of letters that spell “Hello, playground”, so Swift assigns it the type String.

On the other hand, if we want to store someone’s age we might make a variable like this:

var age = 38

That holds a whole number, so Swift assigns the type Int – short for “integer”.

If you have large numbers, Swift lets you use underscores as thousands separators – they don’t change the number, but they do make it easier to read. For example:

var population = 8_000_000

Strings and integers are different types, and they can’t be mixed. So, while it’s safe to change str to “Goodbye”, I can’t make it 38 because that’s an Int not a String.

Hacking with Swift is sponsored by Instabug

SPONSORED Are you tired of wasting time debugging your Swift app? Instabug’s SDK is here to help you minimize debugging time by providing you with complete device details, network logs, and reproduction steps with every bug report. All data is attached automatically, and it only takes a line of code to setup. Start your free trial now and get 3 months off exclusively for the Hacking with Swift Community.

Start your free trial!

Sponsor Hacking with Swift and reach the world's largest Swift community!

BUY OUR BOOKS
Buy Pro Swift Buy Swift Design Patterns Buy Testing Swift Buy Hacking with iOS Buy Swift Coding Challenges Buy Swift on Sundays Volume One Buy Server-Side Swift (Vapor Edition) Buy Advanced iOS Volume One Buy Advanced iOS Volume Two Buy Advanced iOS Volume Three Buy Hacking with watchOS Buy Hacking with tvOS Buy Hacking with macOS Buy Dive Into SpriteKit Buy Swift in Sixty Seconds Buy Objective-C for Swift Developers Buy Server-Side Swift (Kitura Edition) Buy Beyond Code

Was this page useful? Let us know!

Average rating: 4.8/5

Link copied to your pasteboard.