CODEWITHSUNDEEP
swiftdictionary
thedeg123
thedeg123

Reputation: 438

How to make a dictionary containing dictionaries in swift

I attempted the syntax in the following way:

var Days: [String: (Dictonary [Int: Int])] = ["ADay: : [:], "BDay" : [:], "CDay" : [:], "DDay:" : [:]]

I wish to then set them later like so:

Days.ADay = [1:1, 2:2, 3:3, 4:4, 5:5, 6:6, 7:7] Days.BDay: [Int: Int] = [1:8, 2:1, 3:2, 4:3, 5:4, 6:5, 7:13] etc.

Thanks.

Upvotes: 2

Views: 15223

Answers (3)

brandonscript
brandonscript

Reputation: 72855

Creating a nested dictionary in Swift is easy. In its simplest form, the most intuitive way is:

let dict = ["key": ["nestedKey": ":)"]]

In your case, for starters, your quotations are mismatched.

Next, you're overthinking what a dictionary is and how you instantiate it. You're trying to build a predefined dictionary with nested keys (which are actually immutable). If you want to do it your way, don't worry about pre-defining keys. When you're ready to assign, do:

var days: [String: Dictionary] = []
days["ADay"] = [1:1, 2:2, 3:3, 4:4, 5:5, 6:6, 7:7]

If you need something more complex, or something more structured than that, try using a Struct instead. This is the "Swift" way of doing things, allowing you to structure a complex set of conforming (statically typed!) data. Example:

struct Days {
    var ADay = [Int: Int]()
    var BDay = [Int: Int]()
    var CDay = [Int: Int]()
    var DDay = [Int: Int]()
}

var days = Days()

days.ADay = [1:1, 2:2, 3:3, 4:4, 5:5, 6:6, 7:7]

Upvotes: 9

Donovan King
Donovan King

Reputation: 855

If you're looking for a shorthand type declaration it would look like this.

var twodDict: [String : [String : Int]]

In other words:

var twodDict: [OuterKey : [InnerKey : StoredObjectorValue]]

Upvotes: 1

Kristopher Johnson
Kristopher Johnson

Reputation: 82535

Here are your examples with legal syntax:

var Days: [String: [Int: Int]] = ["ADay": [:], "BDay" : [:], "CDay" : [:], "DDay:" : [:]]

Days["ADay"] = [1:1, 2:2, 3:3, 4:4, 5:5, 6:6, 7:7]

Days["BDay"] = [1:8, 2:1, 3:2, 4:3, 5:4, 6:5, 7:13]

Another way to declare your type is var Days: Dictionary<String, Dictionary<Int, Int>>.

Upvotes: 1

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