# Help with Optionals in Structs

**URL:** <https://forums.swift.org/t/help-with-optionals-in-structs/65902>\
**Category:** Using Swift\
**Tags:** structs\
**Created:** [June 30, 2023, 2:17am UTC](https://forums.swift.org/t/help-with-optionals-in-structs/65902 "2023-06-30T02:17:14Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![thehenryfam](https://avatars.discourse-cdn.com/v4/letter/t/3da27b/32.png) [@thehenryfam](https://forums.swift.org/u/thehenryfam)\
**Post date:** [June 30, 2023, 2:17am UTC](https://forums.swift.org/t/help-with-optionals-in-structs/65902/1 "2023-06-30T02:17:14Z")

</div>

Hello, all. First post here. I am a rank beginner at Swift, so please pardon the (probably) simplistic question. I have begun working through the SwiftUI for Masterminds book (3rd Ed.) and am stumped about something. In the introduction to structs, they offer the following example (Listing 3-31, pg. 44):

```swift
struct Price {
     var USD = 0.0
     var CAD = 0.0
}
struct Item {
     var name: String = "Not defined"
     var price: Price?
}
var purchase = Item()
purchase.name = "Lamps"
purchase.price?.USD = 10.50

```

I am confused on a couple points. First, in the results window, it shows that the value after the last assignment statement is still nil rather than 10.50. Secondly, when I tried to print this value with the command print(purchase.price!.USD), I get an execution error: " **Fatal error: Unexpectedly found nil while unwrapping an Optional value**". So it appears the assignment is not working? If I don't reference one struct from another and just combine the members in one struct, I can get it to work as I think it should, so seems to have something to do with the dot notation between the two? I don't know.... any help appreciated. 🙂

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<div class="post-metadata">

**Author:** ![David\_Smith](https://sea2.discourse-cdn.com/swift/user_avatar/forums.swift.org/david_smith/32/37508_2.png) [@David\_Smith](https://forums.swift.org/u/David_Smith)\
**Post date:** [June 30, 2023, 2:29am UTC](https://forums.swift.org/t/help-with-optionals-in-structs/65902/2 "2023-06-30T02:29:10Z")

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If you break your code down into smaller pieces, the last bit ends up being this:

Before:

```swift
purchase.price?.USD = 10.50

```

After:

```swift
var price = purchase.price
if price != nil { //this bit is what the ? does
  price!.USD = 10.50
}
purchase.price = price

```

Hopefully it's clearer in the expanded version why it would remain nil? Somewhere in your code you'll need to actually make a `Price` value using `Price(…)`.

---

<div class="post-metadata">

**Author:** ![thehenryfam](https://avatars.discourse-cdn.com/v4/letter/t/3da27b/32.png) [@thehenryfam](https://forums.swift.org/u/thehenryfam)\
**Post date:** [June 30, 2023, 4:09am UTC](https://forums.swift.org/t/help-with-optionals-in-structs/65902/3 "2023-06-30T04:09:22Z")

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Ok, very interesting. Thanks so much for your reply and breaking it down that way. I think I get the gist of what you are saying. I am just trying to follow the book's examples and understand what's taking place. You mentioned making a Price value using Price somewhere in the code. Not sure I know how or where to do that at this early stage of my learning. Can you tell me what that reference would look like? Thanks again, David.

---

<div class="post-metadata">

**Author:** ![David\_Smith](https://sea2.discourse-cdn.com/swift/user_avatar/forums.swift.org/david_smith/32/37508_2.png) [@David\_Smith](https://forums.swift.org/u/David_Smith)\
**Post date:** [June 30, 2023, 5:13am UTC](https://forums.swift.org/t/help-with-optionals-in-structs/65902/4 "2023-06-30T05:13:10Z")

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> [@thehenryfam](#):
>
> `var purchase = Item()`

You see this bit in the code you already have? That’s how you make an Item. You need to make a Price the same way.