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

    }
}

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

var taxes = Expense.calculateTaxes(item)

1 Answer

Brendan Whiting
seal-mask
.a{fill-rule:evenodd;}techdegree seal-36
Brendan Whiting
Front End Web Development Techdegree Graduate 84,735 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)