Computed property example

ComputedProperty.swift

import Foundation

struct Rectangle {
    var width = 0.0
    var height = 0.0
    
    var area: Double {
        set {
            width = sqrt(newValue)
            height = sqrt(newValue)
        }
        get {
            return width * height
        }
    }
}

var rect = Rectangle()
print(rect.area)
rect.area = 10

print(rect.height)
print(rect.area)