Map array of objects to Dictionary in Swift

Question

I have an array of Person\'s objects:

class Person {
   let name:String
   let position:Int
}

and the array is:

Answer 1

How about a KeyPath based solution?

extension Array {

    func dictionary(withKey key: KeyPath, value: KeyPath) -> [Key: Value] {
        return reduce(into: [:]) { dictionary, element in
            let key = element[keyPath: key]
            let value = element[keyPath: value]
            dictionary[key] = value
        }
    }
}

This is how you will used it:

struct HTTPHeader {

    let field: String, value: String
}

let headers = [
    HTTPHeader(field: "Accept", value: "application/json"),
    HTTPHeader(field: "User-Agent", value: "Safari"),
]

let allHTTPHeaderFields = headers.dictionary(withKey: \.field, value: \.value)

// allHTTPHeaderFields == ["Accept": "application/json", "User-Agent": "Safari"]