Join array using variable separator

Question

I'm trying to join an array using .joined(separator:). However, I want the separator to include the index. For example, if I have the array ["red", "orange", "yellow", "green"], I want the output to be "red (0), orange (1), yellow (2), green". I tried to do .joined(separator: "\($0.index), "), but that didn't work.

Is your output a mistake or do you actually not want the (3) at the end? — rmaddy
– rmaddy, Commented Jun 17, 2019 at 23:20

ielyamani · Accepted Answer · 2019-06-17 23:20:52Z

5

Is this what you want?

let array = ["red", "orange", "yellow", "green"]

let output = array.enumerated()
    .map { $1 + " (\($0))" }
    .joined(separator: ", ")

print(output)   //red (0), orange (1), yellow (2), green (3)

If the last index shouldn't be included, then here is a solution:

let output = (array.dropLast().enumerated()
    .map { $1 + " (\($0))" }
    + [array.last ?? ""])
    .joined(separator: ", ")

edited Jun 17, 2019 at 23:20

answered Jun 17, 2019 at 23:14

ielyamani

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Comments

vacawama · Accepted Answer · 2019-06-18 01:25:24Z

2

You can try

var arr = ["red", "orange", "yellow", "green"]
let num = (0 ..< arr.count - 1).map { " (\($0)), " }
let res = zip(arr,num).map{ $0 + $1 }.joined() + arr.last!

edited Jun 18, 2019 at 1:25

vacawama

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answered Jun 17, 2019 at 23:03

Shehata Gamal

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1 Comment

vacawama Over a year ago

(0 ..< arr.count - 1) can also be written as arr.indices.dropLast()

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