Project a Column from a Swift Array of Tuple

Question

I have a Swift array of tuples, Persons = [(name:String, age:Int)]. Now I would like to extract all distinct names in an array of String, name:[String] from Persons array. How can I get it.

Have you tried anything yet? You could map the array to only extract the `"name"` and then put the result in a set. — luk2302, Apr 28 '16 at 09:47
I don't know how to use map. I think there might be a direct way to do it. I am just wondering — Sazzad Hissain Khan, Apr 28 '16 at 09:49

score 3 · Answer 1 · answered Apr 28 '16 at 09:55

3

Small code example for you how to use map function:

struct Person {
        let name: String
        let age: Int
}

let people = [
    Person(name: "Oleg",  age: 24),
    Person(name: "Igor",    age: 26),
]

let names: [String] = people.map { return $0.name }

answered Apr 28 '16 at 09:55

Oleg Gordiichuk

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As i could notice question is with Swift tag. – Oleg Gordiichuk Apr 28 '16 at 09:58
i know..but i am new to swift – Rajneesh071 Apr 28 '16 at 09:59
1

This is a nice example for you http://stackoverflow.com/questions/6127638/nsarray-equivalent-of-map – Oleg Gordiichuk Apr 28 '16 at 09:59
Actually the OP should use the struct at once rather than the tuple ;-) – vadian Apr 28 '16 at 10:45

score 3 · Accepted Answer · answered Apr 28 '16 at 10:36

3

let distinctNames = Set(Persons.map { $0.name })

answered Apr 28 '16 at 10:36

Alexander Doloz

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Project a Column from a Swift Array of Tuple

2 Answers2