In this tutorial, let’s see how protocol extensions can be used as default and convenient API.
I am taking a Movable protocol which is having a move method.
protocol Movable {
func move(at minimumSpeed: Float)
}
I am creating a class called Car which confirms to Movable protocol.
class Car: Movable {
}
This gives a build error.
We need to implement move method as Car is confirming to Movable.
Instead of this forced implementation, using protocol extensions, we can write default implementation.
extension Movable {
func move(at minimumSpeed: Float) {
print("Moving @ \(minimumSpeed) MPH")
}
}
let car = Car()
car.move(at: 40.0)
This is how we can leverage protocol extensions for default implementations.
Now, What If I don’t want to mention the speed every time. I need to go with minimum speed 40.0 as default speed.
This can also be done using the protocol extensions, by having default value for minimumSpeed.
extension Movable {
func move(at minimumSpeed: Float = 40.0)
{
{
print("Moving @ \(minimumSpeed) MPH")
}
}
let car = Car()
car.move()
Simple and useful. Isn’t it?
Hope this post is useful. Feel free to comment incase of any queries.
