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iOS Swift Enums and Structs Structs and their Methods Struct Methods

William Hartvedt Skogstad
William Hartvedt Skogstad
5,857 Points

I can't figure out where to put the tax percentage.

We need to figure out the tax amount when the tax percentage is 7.5 percent. Call the method calculateTaxes on the variable item and assign the result to a new variable named taxes.

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))


var item = Expense(description: "Gains")
item.amount = 100.0

var taxes = Expense.calculateTaxes(item)

1 Answer

Brendan Whiting
.a{fill-rule:evenodd;}techdegree seal-36
Brendan Whiting
Front End Web Development Techdegree Graduate 84,702 Points

you're calling the calculateTaxes() function on Expense, but you should be calling it on item. Expense is the abstract sctruct, item is the real life instance of an Expense. And then 7.5 is the argument you pass into that function. When you defined this function, you specified that it takes a parameter called percentage which is a Double, and it calculates the taxes based on that number. So inside the parentheses is where you put that number when you call it in real life.

So the code would look like this:

var taxes = item.calculateTaxes(7.5)