Swift - Convert Array to Dictionary

Question

I just want convert an array of Player Names into a dictionary Scoreboard, giving everyone an initial score of 0.

Meaning...

var playerNames =          


        

Answer 1

Based on jmad8 answer

Details

• Swift 5.3
• Xcode 12.0.1 (12A7300)

Solution

extension Sequence {
    func toDictionary<Key: Hashable, Value>(where closure: (Element) -> (Key, Value)) -> [Key: Value] {
        reduce(into: [Key: Value]()) { (result, element) in
            let components = closure(element)
            result[components.0] = components.1
        }
    }
    
    func toCompactDictionary<Key: Hashable, Value>(where closure: (Element) -> ((Key, Value)?)) -> [Key: Value] {
        reduce(into: [Key: Value]()) { (result, element) in
            guard let components = closure(element) else { return }
            result[components.0] = components.1
        }
    }
}

Usage

// Sample 1

print(languages.toDictionary { (string) -> (Character, String) in
    return (string.first!, string)
})

print(languages.toCompactDictionary { (string) -> (Character, String)? in
    guard let character = string.first, character != Character("J") else { return nil }
    return (character, string)
})


// Sample 2

print(languages.enumerated().toDictionary { (data) -> (Int, String) in
    return (data.offset, data.element)
})

// Shorter version of sample 2

print(languages.enumerated().toDictionary { ($0.offset, $0.element) })

// Sample 3

struct Order {
    let id: Int
    let desctiption: String
}

let orders = [
                Order(id: 0, desctiption: "Apple"),
                Order(id: 1, desctiption: "Banana"),
                Order(id: 2, desctiption: "watermelon")
            ]

print(orders.toDictionary { ($0.id, $0) })