Initialize Struct with Array

[sprouse5]

So I have a struct:

struct MyStruct {
    let title: String
    let selected: Bool
}

And an array of strings:

let myStrings = [ "Apple", "Banana", "Carrot" ]

I want to initialize an array of MyStructs with this array of strings, and then false for the selected property. For instance:

var structArray: [MyStruct]?

for string in myStrings {
    let myObject = MyStruct(title: string, selected: false)
    structArray.append(myObject)
}

Is there a better way to do this? I was thinking of trying to use map or filter but I’m not sure if this is the right direction to go. Thanks!

[jessycatterwaul]

map is the way to go! Have you tried it yet?

[sprouse5]

Thanks for that insight! Here is what I ended up with:

struct MyStruct {
    let title: String
    let selected: Bool
}

var myStrings: [String]?

...

// simple version of initializing optional string array
myStrings = [String]()
myStrings?.append("Apple")
myStrings?.append("Banana")
myStrings?.append("Carrot")


guard let mStrings = myStrings else { return }
let structArray = mStrings.map { MyStruct(title: $0, selected: false) }

The thing I think was I missing was the fact that my original string array is an optional, so I added the guard statement before mapping and now it works! Thanks for the help!

[personalcompass]

var myStrings: [String]?
myStrings = [String]()

If you’re just going to initialize it as a non-optional array, why declare it as optional in the first place?

You could just do

var myStrings = [String]()

That would also remove the guard let later on

ALSO

If they’re all going to start off as false, i would suggest creating an initializer with a default value:

init(title: String) {
    self.title = title
    selected = false
}

...

{ MyStruct(title: $0) }

OR just set the value in the declaration:

let selected = false

That way you don’t need to initialize it separately every time.

[personalcompass]

I’ve also created a list of other common swift mistakes (and how to fix them) here:
www.mypersonalcompass.com/swift-mistakes

[sprouse5]

The array myStrings is optional because in my actual code it is initialized via a network call, so there’s the chance it could be nil. I kept that out for this simple example.

I added the init function to MyStruct, thanks for that! It now looks like this:

struct MyStruct: Codable {
    let title: String
    var selected = true

    init(title: String) {
        self.title = title
    }

    mutating func setSelected(_ value: Bool) {
        selected = value
    }
}

[personalcompass]

At that point wouldn’t it be easier to make it a class? That way you don’t need a fancy setter with the mutating keyword.