Swift [map] return array containing values of specific property

Question

Say i have an array for objects

let persons = [Person]

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

And i wanna return array of strings [String] containing persons' names whose position is equal to 1. If there any way to do this using map/flatmap/reduce functions?

When posting a question like this you should include your own attempt at solving the issue instead of treating stackoverlow like a free code writing service. — Joakim Danielson, Jun 04 '20 at 10:49

score 1 · Answer 1 · answered Jun 04 '20 at 10:24

1

Here's how:

let names = persons
    .filter { $0.position == 1 }
    .map { $0.name }

answered Jun 04 '20 at 10:24

Frankenstein

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score 1 · Accepted Answer · answered Jun 04 '20 at 10:26

1

To avoid two steps use compactMap

let positionOneNames = persons.compactMap{$0.position == 1 ? $0.name : nil }

answered Jun 04 '20 at 10:26

vadian

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thank you! that's exactly what i need – eugene_prg Jun 04 '20 at 10:28
Good method! As the code becomes more complex readability reduces. – Frankenstein Jun 04 '20 at 10:29

Swift [map] return array containing values of specific property

2 Answers2