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iOS Intermediate Swift 2 Extensions and Protocols Protocol Extensions

Sheng Wei
Sheng Wei
4,382 Points

[Help!] How to write return statement for Math protocol extension?

Help please!

protocols.swift
protocol Math {
  func square(value: Double) -> Double
}

// Enter your code below

extension Math {
     func square(value: Double) -> Double {
        return self 
    }
}

1 Answer

Steven Deutsch
Steven Deutsch
21,046 Points

Hey Sheng Wei,

You're close, you're just not returning the right value. By using self here you would be returning the instance which the method was called on, which won't be of type Double. The thing that makes the most sense here would be to return the square of the value, value * value.

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

// Enter your code below

extension Math {
  func square(value: Double) -> Double {
    return value * value
  }
}

Good Luck

Sheng Wei
Sheng Wei
4,382 Points

Thanks Steven! :)