NSArray Equivalent of Map

Question

Given an NSArray of NSDictionary objects (containing similar objects and keys) is it possible to write perform a map to an array of specified key?

Answer 1

Swift introduces a new map function.

Here is an example from the documentation:

let digitNames = [
    0: "Zero", 1: "One", 2: "Two",   3: "Three", 4: "Four",
    5: "Five", 6: "Six", 7: "Seven", 8: "Eight", 9: "Nine"
]
let numbers = [16, 58, 510]

let strings = numbers.map {
    (var number) -> String in
    var output = ""
    while number > 0 {
        output = digitNames[number % 10]! + output
        number /= 10
    }
    return output
}
// strings is inferred to be of type String[]
// its value is ["OneSix", "FiveEight", "FiveOneZero"]

The map function takes a closure which returns a value of any type and maps the existing values in the array to instances of this new type.