Swift Class Properties
Swift Class Properties
Store state in class properties. Use static for type properties shared across all instances.
Stored and Computed
Use var for stored properties and let for constants.
Example
class User {
var name: String // stored
var greeting: String { "Hello, \(name)" } // computed
static var appName = "MyApp" // type property
init(name: String) { self.name = name }
}Property Observers
Use willSet and didSet to react to changes on stored properties.
Example
class Player {
var score: Int = 0 {
willSet { print("About to set to \(newValue)") }
didSet { print("Changed from \(oldValue) to \(score)") }
}
}
let p = Player()
p.score = 10
