CODEWITHSUNDEEP
iosarraysswift
Artem Novichkov
Artem Novichkov

Reputation: 2341

Extension for replacing by index set

I want to add an extension for Array to replace elements by index set:

extension Array {
    mutating func replace(newElements: [Element], at indexes: IndexSet) {
        //implementation here
    }
}

And an example of using:

var set: IndexSet = [2, 1]
var array = ["0", "1", "2", "3", "4"]
array.replace(newElements: ["@", "%"], at: set) // custom method from future extension
print(array) //Prints ["0", "%", "@", "3", "4"]

But I have trouble with getting element from IndexSet by index. How I can do it? Or maybe you know more elegant solution for replacing elements in array. I'm using IndexSet instead Array<Int> because later I'll use it for replacing sections in UITableView.

Upvotes: 0

Views: 131

Answers (2)

T. Benjamin Larsen
T. Benjamin Larsen

Reputation: 6393

As @Alexander mentions above it makes little sense to use an IndexSet as this is not ordered. What you probably want is an array of Ints for each index. That should leave you with something like this:

extension Array {
    mutating func replace(newElements: [Element], at indexes: [Int]) {
        for (index, position) in indexes.enumerated() {
            guard position < count else {
                // error handling
                return
            }

            remove(at: position)
            insert(newElements[index], at: position)
        }
    }
}

Upvotes: 0

Tj3n
Tj3n

Reputation: 9943

There's nothing wrong with using [Int] instead of IndexSet, when you use this, you have to use sth like indexes.index(indexes.startIndex, offsetBy: 1) to access the index, very annoying, I advised just use [Int] like other array function and throws error when the value is out of bounds

Upvotes: 1

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