Arrays
Arrays are collections of values that are stored as a single value. For example, John, Paul, George, and Ringo are names, but arrays let you group them in a single value called The Beatles.
In code, we write this:
let john = "John Lennon"
let paul = "Paul McCartney"
let george = "George Harrison"
let ringo = "Ringo Starr"
let beatles = [john, paul, george, ringo]That last line makes the array: it starts and ends with brackets, with each item in the array separated by a comma.
You can read values from an array by writing a number inside brackets. Array positions count from 0, so if you want to read “Paul McCartney” you would write this:
beatles[1]Be careful: Swift crashes if you read an item that doesn’t exist. For example, trying to read beatles[9] is a bad idea.
Note: If you’re using type annotations, arrays are written in brackets: [String], [Int], [Double], and [Bool].
SPONSORED Fernando's book will guide you in fixing bugs in three real, open-source, downloadable apps from the App Store. Learn applied programming fundamentals by refactoring real code from published apps. Hacking with Swift readers get a $10 discount!
Sponsor Hacking with Swift and reach the world's largest Swift community!
