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Bruce Röttgers
18,211 PointsStuck in Challenge 1, what is false with the method?
I'm trying to solve that, but I don't understand how I can give an external argument as an underscore.
// Declare protocol here
protocol ColorSwitchable {
func switchColor(color: Color) {
}
}
enum LightState {
case on, off
}
enum Color {
case rgb(Double, Double, Double, Double)
case hsb(Double, Double, Double, Double)
}
class WifiLamp {
let state: LightState
var color: Color
init() {
self.state = .on
self.color = .rgb(0,0,0,0)
}
}
1 Answer
Royce Pollard
24,267 PointsHello,
Your in the right direction!
To omit the external name you do use an underscore. For example:
func someFunction(external local: String) {}
Where the "external" is what will show when you can the fund and initialize it. When you call it it looks like this:
someFunciton(external: String)
to omit it you use the underscore; someFunction(_ local: String)
Then it will show: someFunction( )
The "local" is the name you use in the fund when you are creating the body of the method. But in the code it looks like
someFunction(external local: String) { return "This is (local)'s function." }
protocol ColorSwitchable { func switchColor( _ color: Color) }
Bruce Röttgers
18,211 PointsBruce Röttgers
18,211 PointsAlready tried that but it gives me a compiler error
Royce Pollard
24,267 PointsRoyce Pollard
24,267 PointsOk I see the problem. Trying using the underscore again.
This time remember in protocols they are more like guidelines to ensure certain objects adhere to certain structuring. They do not have to be implemented in the protocol. Only when you create the object that adheres to the protocol will you have to create an implementation for the protocols restrictions.
for example:
protocol SomeName { func getNames(_ names: Array) }
// You're are just saying an object has to implement this func somehow. Meaning No parentheses
But not:
protocol SomeName { func getNames(_ names: Array) { // You do not need to provide implementation in the protocol itself. } }
Short and sweet: You do not need the parentheses at the end of your method in the protocol.