CODEWITHSUNDEEP
iosswiftswift3
theDC
theDC

Reputation: 6484

Comparing two array and matching elements based on boolean

Let's say I have two arrays

let array1 = [1,2,3]
let array2 = [false, true, false]

I'd like to return the list of values from array1 that matches true boolean at certain index. In this simple example this would be [2]

How to achieve it using functional approach?

Upvotes: 1

Views: 339

Answers (1)

Martin R
Martin R

Reputation: 540075

"Zip" the arrays, then map each pair to the first element or nil, depending on the second element. flatMap() returns only the non-nil results:

let array1 = [1,2,3]
let array2 = [false, true, false]

let result = zip(array1, array2).flatMap { $1 ? $0 : nil }
print(result) // [2]

Upvotes: 6

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