How do I check in Swift if two arrays contain the same elements regardless of the order in which those elements appear in?

Swift 3, 4

extension Array where Element: Comparable {
    func containsSameElements(as other: [Element]) -> Bool {
        return self.count == other.count && self.sorted() == other.sorted()
    }
}

// usage
let a: [Int] = [1, 2, 3, 3, 3]
let b: [Int] = [1, 3, 3, 3, 2]
let c: [Int] = [1, 2, 2, 3, 3, 3]

print(a.containsSameElements(as: b)) // true
print(a.containsSameElements(as: c)) // false

---

you can do something like this:

  array1.sortInPlace()
  array2.sortInPlace()

  print(array1,array2)

  if array1 == array2 {
    print("equal")
  } else {
  print("not equal") 
  }

and if don't want change origional array we can do

 let sorted1 = array1.sort()
 let sorted2 = array2.sort()

  if sorted1 == sorted2 {
    print("equal")
  }else {
    print("not equal")
  }

Using Set

let array1 = ["a", "b", "c"]
let array2 = ["b", "c", "a", "c"]

let set1 = Set(array1)
let set2 = Set(array2)

if (set1.count == set2.count && set1 == set2) { //if you compare big sets it is recommended to compare the count of items in the sets beforehand
    //they are identical
}

The Set implements Hashable so the task is to implement the hash function to work with a Set