I have two arrays:

@State var myInterests: [String] = ["Beer", "Food", "Dogs", "Ducks"]
@State var otherInterests: [String] = ["Ducks", "Baseball", "Beer", "Pasta"]

I need to display a list with all shared interests listed first (top of the list), and then the others after.

ForEach(interests, id: \.self) { tag in
   Text(tag)
}

The result for otherInterests should be something like:

["Ducks", "Beer", "Baseball", "Pasta"]

Is there any way of sorting the array to move the shared interests to the front of the array and the remaining ones after?

CodePudding user response：

As long as the order of the subitems is not that important (you can sort each sublist to make sure consistent output) - a simple solution can be to use sets here!

Something like this

let myInterests: [String] = ["Beer", "Food", "Dogs", "Ducks"]
let otherInterests: [String] = ["Ducks", "Baseball", "Beer", "Pasta"]
// This will result only in the shared interests between my and other
let sharedInterests = Set(myInterests).intersection(Set(otherInterests))
// This will result in only the not shared interests
let resetOfOtherInterest = Set(otherInterests).subtracting((Set(sharedInterests)))
// Here we combine the two (which are disjoint!)
let newOtherInterest = Array(sharedInterests)   Array(resetOfOtherInterest)

print(newOtherInterest)

newOtherInterest = ["Ducks", "Beer", "Baseball", "Pasta"]

CodePudding user response：

if you want to sort by keeping the order of the otherInterests array , You can use below code ()

var myInterests: [String] = ["Beer", "Food", "Dogs", "Ducks"]
var otherInterests: [String] = ["Ducks", "Baseball", "Beer", "Pasta"]

var sortedIndexCount = 0
otherInterests = otherInterests.enumerated().reduce(into: [String]() ){ 
(result, element)  -> Void in
    result.append(element.element)
    if !myInterests.contains(element.element)
    {
        sortedIndexCount  = 1
    }else{
        result.remove(at: element.offset)
        result.insert(element.element, at: sortedIndexCount)
   }
}

print(otherInterests)

Output is :

["Ducks", "Beer", "Baseball", "Pasta"]

Im not sure to use reduce approach but it works