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

Switch statements

If you have several conditions using if and else if, it’s often clearer to use a different construct known as switch case. Using this approach you write your condition once, then list all possible outcomes and what should happen for each of them.

To try this out, here’s a weather constant containing the string sunny:

let weather = "sunny"

We can use a switch block to print one of four different messages:

switch weather {
case "rain":
    print("Bring an umbrella")
case "snow":
    print("Wrap up warm")
case "sunny":
    print("Wear sunscreen")
default:
    print("Enjoy your day!")
}

In that example, the last case – default – is required because Swift makes sure you cover all possible cases so that no eventuality is missed off. If the weather is anything other than rain, snow, or sun, the default case will be run.

Swift will only run the code inside each case. If you want execution to continue on to the next case, use the fallthrough keyword like this:

switch weather {
case "rain":
    print("Bring an umbrella")
case "snow":
    print("Wrap up warm")
case "sunny":
    print("Wear sunscreen")
    fallthrough
default:
    print("Enjoy your day!")
}
Hacking with Swift is sponsored by NSSpain

SPONSORED Announcing NSSpain 2020: Remote Edition! An online, continuous conference for iOS developers. We’ll start on Thursday and finish on Friday, with talks, activities, and lots of fun for 36 hours, non-stop. Sound good? Join us!

Find out more

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.