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iOS Swift Enums and Structs Structs and their Methods Struct Methods

Posted by Pam Selle
Pam Selle
2,123 Points

swift_lint.swift:14:25: error: 'Double' is not convertible to '()' return (self.amount * (percentage/100)) What?

I get this error in the practice code, but also in my playground ... and then it went away after a few tries. What's happening here?

struct.swift 
struct Expense {
    var description: String
    var amount: Double = 0.0

    init (description: String) {
        self.description = description
    }

    // add the calculateTaxes method here
    // it should accept only one parameter named 'percentage' of type Double
  func calculateTaxes(percentage:Double) {
    return (self.amount * (percentage/100))
  }
}

2 Answers

Stephen Whitfield
Stephen Whitfield
16,771 Points

The problem is that you're returning a Double in your calculateTaxes function but you haven't told the compiler that. 

struct Expense {
    var description: String
    var amount: Double = 0.0

    init (description: String) {
        self.description = description
    }

    // add the calculateTaxes method here
    // it should accept only one parameter named 'percentage' of type Double
    func calculateTaxes(percentage:Double) -> Double {
        return (self.amount * (percentage/100))
    }
}
Pam Selle
Pam Selle
2,123 Points
Pam Selle
Pam Selle
2,123 Points

Thanks! That error confused me, is () a type?

Update: Thank you, Stephen!

Stephen Whitfield
Stephen Whitfield
16,771 Points

Yes. It is type Void.