CODEWITHSUNDEEP
swiftdictionary
Elsa Martins
Elsa Martins

Reputation: 61

convert [(key: String, value: String)] in [String:String]

I want convert [(key: String, value: String)] in [String:String] is possible to do ? If yes how i make ? thanks

var KeyValuePair: [(key: String, value: String)] = [(key: "2017 01 04", value: "143.65"), (key: "2017 01 05", value: "140.78"), (key: "2017 01 06", value: "150.23")]

in 

var dictionary: [String:String] =  ["2017 01 04":"143.65", "2017 01 05":"140.78", "2017 01 06":"150.23"]

Upvotes: 3

Views: 3611

Answers (3)

Alexander
Alexander

Reputation: 63321

Swift 4:

If you are sure the the keys are unique, you can use Dictionary.init(uniqueKeysWithValues:):

let dict = Dictionary(uniqueKeysWithValues: keyValuePairs)

Otherwise, you can use Dictionary.init(_:uniquingKeysWith:) instead, which allows you to specify how to handle collisions.

let dict = Dictionary(keyValuePairs, uniquingKeysWith: { previous, new in
    return new //always takes the newest value for a given key
})

Upvotes: 8

XmasRights
XmasRights

Reputation: 1509

The one line functional approach would be:

let dictionary = keyValuePair.reduce([String : String]())
                 {  acc, item in
                    var output = acc
                    output.updateValue(item.value, forKey: item.key)
                    return output
                 }

You could also neaten things up by implementing an extension to Dictionary

extension Dictionary
{
    func appending(value: Value, key: Key) -> Dictionary
    {
        var mutable = self
        mutable.updateValue(value, forKey: key)
        return mutable
    }
}

let dictionary = keyValuePair.reduce([String : String]()) { $0.appending(value: $1.value, key: $1.key) }

Upvotes: 2

David Pasztor
David Pasztor

Reputation: 54745

You just need to iterate through the array of tuples and set the key-value pair of your dictionary with the values of the tuple.

var keyValuePairs: [(key: String, value: String)] = [(key: "2017 01 04", value: "143.65"), (key: "2017 01 05", value: "140.78"), (key: "2017 01 06", value: "150.23")]

var dictionary = [String:String]()
keyValuePairs.forEach{
    dictionary[$0.0] = $0.1
    //since you have named tuples, you could also write dictionary[$0.key] = $0.value
}
print(dictionary)

Please make sure you conform to the Swift naming convention, which is lower-camelcase for variable names.

Upvotes: 8

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