Why does Pasan use an extension?

Question

In the build a weather app it starts with this code:
import Foundation
import UIKit
struct CurrentWeather {
    let temperature: Double
    let humidity: Double
    let precipProbability: Double
    let summary: String
    let icon: String
}
extension CurrentWeather {
    var iconImage: UIImage {
        switch icon {
        case "clear-day": return #imageLiteral(resourceName: "clear-day")
        case "clear-night": return #imageLiteral(resourceName: "clear-night")
        case "rain": return #imageLiteral(resourceName: "rain")
        case "snow": return #imageLiteral(resourceName: "snow")
        case "sleet": return #imageLiteral(resourceName: "sleet")
        case "wind": return #imageLiteral(resourceName: "wind")
        case "fog": return #imageLiteral(resourceName: "fog")
        case "cloudy": return #imageLiteral(resourceName: "cloudy")
        case "partly-cloudy-day": return #imageLiteral(resourceName: "partly-cloudy-day")
        case "partly-cloudy-night": return #imageLiteral(resourceName: "partly-cloudy-night")
        default: return #imageLiteral(resourceName: "default")
        }
    }
}
Why is using an extension preferred over writing the same code inside the struct?

Marcus Klausen · Answer

Hi,
The computed property, is used to help setting the right value for icon property.
But it isn't really in itself part of the CurrentWeather type.
You could think of it like a helper method, like when we break down big functions so that we have better reusability and the code is easier to read.
Cheers :-)

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Juan Jimenez

Juan Jimenez

Why does Pasan use an extension?

1 Answer

Marcus Klausen

Marcus Klausen