Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

iOS Intermediate Swift 2 Extensions and Protocols Protocol Extensions

Protocol Extensions Code Challenge

Am I doing this right?

import Foundation
protocol Math {
    func square(value: Double) -> Double

extension Math {
    func square(let value: Double) -> Double {
        return sqrt(value)

1 Answer

Jason Anders
Jason Anders
Treehouse Moderator 145,858 Points

Hey Stuart,

You're on the right track, but there are just a couple of things.

First, when you are putting the function into the extension, you are not declaring a variable, so the let keyword needs to be deleted. You are just following the Protocol, so you just need to write the function exactly as it is above.

Second, you are not returning the square of the value (you are returning a square root). It should be return value * value

Fix those up, and you're good to go! Good Job!


Oh I see, thanks for those tips!