Computed properties

We just created a Sport struct like this:

struct Sport {
    var name: String
}

That has a name property that stores a String. These are called stored properties, because Swift has a different kind of property called a computed property – a property that runs code to figure out its value.

We’re going to add another stored property to the Sport struct, then a computed property. Here’s how that looks:

struct Sport {
    var name: String
    var isOlympicSport: Bool

    var olympicStatus: String {
        if isOlympicSport {
            return "\(name) is an Olympic sport"
        } else {
            return "\(name) is not an Olympic sport"
        }
    }
}

As you can see, olympicStatus looks like a regular String, but it returns different values depending on the other properties.

We can try it out by creating a new instance of Sport:

let chessBoxing = Sport(name: "Chessboxing", isOlympicSport: false)
print(chessBoxing.olympicStatus)

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!