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iOS Swift Enums and Structs Structs and their Methods Struct Methods

Nuttakit Luengwitayakorn
Nuttakit Luengwitayakorn
1,626 Points

My code doesn't work

My code doesn't work please help

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

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

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


1 Answer

Stone Preston
Stone Preston
42,016 Points

in your function body you are returning a double, however your function does not have its return type declared. add the return type

the swift eBook states:

You indicate the function’s return type with the return arrow -> (a hyphen followed by a right angle bracket), which is followed by the name of the type to return.

so to return a double you would use

func calculateTaxes ( percentage : Double ) -> Double {
        return self.amount * (percentage/100)

Thanks Stone Preston . Totally confused. Challenge says: "add a method named calculateTaxes which accepts a parameter named 'percentage' of type Double and does not return anything"

So why do you add this line if it says to not return anything?

return self.amount * (percentage/100)

And why do you have to declare the type Double twice in the first line?