Is it possible to remove duplicate values from Array with nil values

Question

Array can be any type like

let myArray1 = [ 1, 2, 3, 1, 2, 1, 3, nil, 1, nil]
let myArray2 = [ 1, 2.0, 1, 3, 1.0, nil]

After removing duplicate values from the array, the new array should be:

Output -

 [ 1, 2, 3, nil ]

• Sharad Chauhan: please check related questions : stackoverflow.com/questions/25738817/…
• Pratik Panchal: i tried this link as well stackoverflow.com/questions/25738817/…
• Pratik Panchal: in my array i have nil value as well
• David Pasztor: Do you want to keep the initial ordering of the Array?
• Pratik Panchal: yes i manage ordering also

Answer 1

@Daniel's solution as a generic function:

func uniqueElements<T: Equatable>(of array: [T?]) -> [T?] {
 return array.reduce([T?]()) { (result, item) -> [T?] in
 if result.contains(where: {0ドル == item}) {
 return result
 }
 return result + [item]
 }
}
let array = [1,2,3,1,2,1,3,nil,1,nil]
let r = uniqueElements(of: array) // [1,2,3,nil]

• Pratik Panchal: Alternate is that possible using extension of sequence.?
• Gereon: Would be interested to see that myself, I haven't found a way to express this so far.

Answer 2

You can use this reduce to remove duplicated entries:

myArray.reduce([Int?]()) { (result, item) -> [Int?] in
 if result.contains(where: {0ドル == item}) {
 return result
 }
 return result + [item]
}

output: [1, 2, 3, nil]

• Pratik Panchal: type is not specify it can be dynamic like int, double or it can be String of array
• Pratik Panchal: Array can be Any Type like 1) let myArray1 = [1,2,3,1,2,1,3,nil,1,nil] or 2) let myArray2 = [1,2.0,1,3,1.0,nil]

Answer 3

Please check this code, I have used NSArray after getting filtered array you can convert into swift array

 let arr = [1, 1, 1, 2, 2, 3, 4, 5, 6, nil, nil, 8]
 let filterSet = NSSet(array: arr as NSArray as! [NSObject])
 let filterArray = filterSet.allObjects as NSArray //NSArray
 print("Filter Array:\(filterArray)")

• Gereon: This does not preserve the order of elements.