CODEWITHSUNDEEP
iosarraysswiftdictionarynested
Apple
Apple

Reputation: 123

How to store nested dictionary value

I want to store the value of a nested dictionary so my collection view can use it later without having to loop through stuff to find it every time. I also don't think it'll work (i could be wrong tho) if i try to put the loop in my cellforindexatpath function. The "let abilitiesArray: [Ability] =....." is inside my class

Ultimately I want abilitiesArray = abilities. "heroForDetails.hero.abilities" is a [String: [Ability]] so I want to return the [Ability] whose heroForDetails.hero.id == heroId because there are multiple key: value pairs in heroForDetails.hero.abilities. The current error is missing return in closure expected to return [Ability].

let abilitiesArray: [Ability] = { () -> ([Ability]) in
    let val = heroForDetails.hero.abilities
    for (heroId, abilities) in val {

        if heroForDetails.hero.id == heroId {
            return abilities
        }
    }
}()

"abilities" is an array that I plan to use like so

   func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
    if let cell = collectionView.dequeueReusableCellWithReuseIdentifier("AbilitiesCell", forIndexPath: indexPath) as? AbilitiesCell {

        let ability: Ability
        ability = abilitiesArray[indexPath.row]
        cell.configureCell(ability)
        return cell

    }else {
        return UICollectionViewCell()
    }
}

I hope i did a good job at explaining this. I just started learning to code so Any help would be great. I could be going about this completely wrong too.

Upvotes: 1

Views: 55

Answers (2)

Brian Gorman
Brian Gorman

Reputation: 824

You can access the dictionary by

let val = heroForDetails.hero.abilities let abilities = val[heroForDeails.hero.id]

As far as accessing it in your cellforindexatpath, it should be just fine. Don't worry about the closure.

Upvotes: 0

Sweeper
Sweeper

Reputation: 272555

In your first code snippet, you seem to be finding an item in the val dictionary using a key. I hope that's what you want to do. To do that, you don't need to loop through the whole dictionary. It's very slow to do so. (O(n)) You can use the subscript to access the dictionary using a key (the heroForDeails.hero.id variable). This is much faster (O(1)).

You can shorten the whole snippet into one line:

let abilitiesArray = heroForDetails.hero.abilities[heroForDetails.hero.id]!

Also, I don't see a question in your post...

Upvotes: 1

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