Find Duplicate Elements In Array Using Swift

Question

How to find Duplicate Elements in Array? I have array of phone numbers so in the phone numbers i should start searching from the right side to the left side and find similar

Answer 1

Antoine's solution in Swift 3+ syntax

extension Array {

    func filterDuplicates(includeElement: @escaping (_ lhs: Element, _ rhs: Element) -> Bool) -> [Element] {

        var results = [Element]()

        forEach { (element) in

            let existingElements = results.filter {
                return includeElement(element, $0)
            }

            if existingElements.count == 0 {
                results.append(element)
            }
        }
        return results
    }
}