How to create an array by multiplying another array in a functional way?

Question

I'd like to create an array that contains elements from another array multiplied by some Int value.

Example:

the following code

let arr = [1,2,3]
let multiplier = 3
print(function(arr, multiplier))

should return

[1,2,3,1,2,3,1,2,3]

I know how to make it using nested for loops, but I'm looking for some nifty functional way. I was thinking about map() function, but it iterates over each element of a given array, which is not my use case I suppose.

The duplicate question even has the same example (i.e., repeating `[1,2,3]` three times). — Nicolas Miari, Sep 05 '17 at 10:42
Check this link https://stackoverflow.com/questions/37095943/repeating-array-in-swift — KethanKumar, Sep 05 '17 at 10:45
pls check this link https://stackoverflow.com/a/37096237/2713046 — Balaji Kondalrayal, Sep 05 '17 at 10:49

score 1 · Answer 1 · answered Sep 05 '17 at 10:42

1

Main idea:

Create array of arrays,
flatMap to one-dimensional array.

Example:

let arr = [1, 2, 3]
let multiplayer = 3
print(Array(repeating: arr, count: multiplayer).flatMap({ $0 }))

answered Sep 05 '17 at 10:42

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How to create an array by multiplying another array in a functional way?

1 Answers1