swift check if two array contains Same element and get the element?

Question

How can I compare two arrays in swift which have a common element and get that element?

let a1 = [1, 2, 3]
let a2 = [4, 2, 5]

I want to compare a1 and a2 and get result 2 from comparison in swift 2.2. How?

http://stackoverflow.com/questions/25714985/how-to-determine-if-one-array-contains-all-elements-of-another-array-in-swift — Bhavin Bhadani, Dec 28 '16 at 05:32
Check it http://stackoverflow.com/questions/32439289/how-to-get-list-of-common-elements-of-2-array-in-swift?rq=1 — Amanpreet, Dec 28 '16 at 05:33

ERbittuu · Accepted Answer · 2016-12-28T05:50:03.697

23

You can use filter function of swift

let a1 = [1, 2, 3]
let a2 = [4, 2, 5]

let a = a1.filter () { a2.contains($0) }

print(a)

print : [2]

if data is

let a1 = [1, 2, 3]
let a2 = [4, 2, 3, 5]

print : [2, 3]

If you want result in Int not in array

let result = a.first

You get optional Int(Int?) with result of first common element

edited Dec 28 '16 at 05:50

answered Dec 28 '16 at 05:37

ERbittuu

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19

1

Yes, It is work for all array. condition is only both array are same type. Here is [Int] array – ERbittuu Dec 28 '16 at 05:42
How can i get a not in array but simple Int? – Istiak Morsalin Dec 28 '16 at 05:42
@JasonBourne Is your arrays have only one common object? – Nirav D Dec 28 '16 at 05:43
Lets say it has one common object – Istiak Morsalin Dec 28 '16 at 05:45
Here always possibility of getting more then one elements same in both array. So it will always return array. – ERbittuu Dec 28 '16 at 05:46
But if you want only first element or must one same element then use let first = a.first – ERbittuu Dec 28 '16 at 05:46
1

You should use a `Set` to speed up the `.contains()` call. – Alexander Dec 28 '16 at 05:57

score 4 · Answer 2 · answered Mar 06 '20 at 13:01

Another alternative would to use Sets:

let a1 = [1, 2, 3]
let a2 = [4, 2, 5]

let a = Set(a1).intersection(Set(a2)) // <- getting the element itself
print(a) // 2

let contains: Bool = !Set(a1).isDisjoint(with: Set(a2)) // <- checking if they have any common element
print(contains) // true

swift check if two array contains Same element and get the element?

2 Answers2