How to determine if one array contains all elements of another array in Swift?

Question

I have 2 arrays:

var list:Array = [1,2,3,4,5]
var findList:Array = [1,3,5]

I want to determine if list A

Answer 1

If you need to determine, that one array is subArray of another.

public extension Array where Element: Equatable {

    func isSuperArray(of array: Array) -> Bool {

        guard
            count >= array.count,
            let indexes = array.first.flatMap(indexes(of:)),
            !indexes.isEmpty else {
                return false
        }

        let arraysForComparison = indexes
            .compactMap { index -> [Element]? in
                guard index + (array.count - 1) <= count else { return nil }
                return Array(self[index..<(index + array.count)])
        }

        return arraysForComparison.contains(array)
    }

    func isSubArray(of array: Array) -> Bool {
        array.isSuperArray(of: self)
    }

    private func indexes(of element: Element) -> [Index] {
        enumerated()
            .filter { element == $0.1 }
            .map { index, _ in index }
    }
}

Example of usage:

let array1 = [1, 2, 3, 4]
let array2 = [2, 3]

print(array1.isSuperArray(of: array2)) // true
print(array2.isSubArray(of: array1)) // true

print(array2.isSuperArray(of: array1)) // false
print(array1.isSubArray(of: array2)) // false