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iOS Swift Enums and Structs Structs Stored Properties

Posted by Rhew Deigl
Rhew Deigl
1,047 Points

How Is This Wrong?

When checked, the system tells me that it can't be compiled. I am wondering what I did wrong.

struct.swift 
struct Expense {
    var description = "String"
    var amount = "Double"
}
var travel = Expense(description: "Flight to Cupertino", amount: 500.00)
Knut Olaf Lien
Knut Olaf Lien
7,743 Points
Knut Olaf Lien
Knut Olaf Lien
7,743 Points

Did you mean to pass inn amount as String or as Double type? Try this: 

struct Expense {
    var description = "String"
    var amount = "Double"
}
var travel = Expense(description: "Flight to Cupertino", amount: "500.00")

Or this:

struct Expense {
    var description = "String"
    var amount = 123.0
}
var travel = Expense(description: "Flight to Cupertino", amount: 500.0)

2 Answers

Greg Kaleka
Greg Kaleka
39,021 Points
Greg Kaleka
Greg Kaleka
39,021 Points

Hi Rhew,

In your struct definition, you are setting default values for the two properties of the string literals "String" and "Double". Note you're setting them to the strings "String" and "Double", not the data types String and Double. This would be just like setting them to "Potato" and "Monkey". Not only is this not what you're trying to do, but for this challenge, there's no need to set default values.

What you want to instead of assigning them values define their types. You do this with a colon, and since String and Double are keywords, there's no need for quotation marks (in fact you need to not use them).

solution.swift 
struct Expense {
    var description: String
    var amount: Double
}

var travel = Expense(description: "Flight to Cupertino", amount: 500.00)

We're declaring the variables and just telling Swift what kind of variables they should be when initialized.

Let me know if this makes sense!

Best,

Greg

Knut Olaf Lien
Knut Olaf Lien
7,743 Points
Knut Olaf Lien
Knut Olaf Lien
7,743 Points

Note that you can set default values in a struct if this is what you want: 

struct Expense {
    var description = "Flight to Cupertino"
    var amount = 500.0
}

var travel = Expense()

This will set the same values every time you declare an Expense variable. You can still override its values if you need.

Greg Kaleka
Greg Kaleka
39,021 Points
Greg Kaleka
Greg Kaleka
39,021 Points

Thanks Knut - you're correct. I've updated my answer in light of this.