insert item at multiple indices into an array

Question

For example I have an array arr = [1,2,3,4,5,6,7,8,9,10] and I want to add the number 12 at position 0, 5, 8 and 9.

To achieve this I tried

extension Array {
    mutating func remove(_ newElement: Element, at indexes: [Int]) {
        for index in indexes.sorted(by: >) {
            insert(_ newElement: Element, at: index)
        }
     }
  }

But then I get the error: Ambiguous reference to member 'insert(_:at:) in the 4th line. Is it possible to do this in this way ? I use Xcode 9.2

Answer 1

Your insert function is not currently receiving an element argument. You are using the insert function, not declaring it. I also renamed your function for use clarification.

var arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

extension Array {
    mutating func add(_ newElement: Element, at indices: [Int]) {
        for index in indices(by: >) {
            insert(newElement, at: index)
        }
    }
}

arr.add(12, at: [0, 5, 8, 9])
print(arr)

Answer 2

Try something like this:

extension Array{
    mutating func replaceElements(atPositions: [Int], withElement: Element){
        for item in atPositions{
            self.remove(at: item)
            self.insert(withElement, at: item)
        }
    }
}

Please note that your don't necessarily need to use the self keyword; it was only used for clarity.