FlatMap Struct Multiple Properties

[sprouse5]

So I have a struct:

struct Category {
    let title: String
    let icons: [String]
}

And I want to extract all the strings out of it in order. For instance:

var categories = [Category]()
categories += [Category(title: "Title1", icons: ["icon1", "icon2"])]
categories += [Category(title: "Title2", icons: ["icon3", "icon4"])]

let strings = categories.flatMap({ [$0.title, $0.icons] })

What I want is:
["Title1", "icon1", "icon2", "Title2", "icon3", "icon4"]

But I keep getting:
["Title1", ["icon1", "icon2"], "Title2", ["icon3", "icon4"]]

Is this even possible? Thanks!

[jayantvarma]

Hi @sprouse5,
if you write code, you can basically do whatever you want, so the short answer is yes, you can so that.

However it is a bit unusual to flatten all the elements.

update the code below into your code
let strings = categories.flatMap({ [$0.title, $0.icons.first!, $0.icons.last!] })
However this relies on the fact that you have exactly 2 elements in the icons array

cheers,

Jayant

[sprouse5]

Thanks for your reply! I’m flattening all the strings that I’m reading in from a plist file to get a single string array of categories for use in filtering later on in the app. My solution was to create a computed property like this:

struct Category {
    let title: String
    let icons: [String]

    var names: [String] {
        var strings = icons
        strings.insert(title, at: 0)
        return strings
    }
}

I create a copy of the icons array, add the title to the beginning of it, and return it. That way I can flat map like so:

let data = categories.flatMap { $0.names }

If there’s a better/more efficient way to do this I’d like to know, as I’m trying to create this app using iOS best practices. Thanks for your time!

[sgerrard]

You can do it in one line with no extra property:

let data = categories.flatMap { [$0.title] + $0.icons }

The closure makes a one element array of title, then adds the icons array to that, much like your computed property.

[sprouse5]

Thanks so much @sgerrard! This is exactly what I was after.