Swift: Extending Array, Value of type _ has no member _

Question

I'm trying to extend Array to return a sub array. the line let b = arr.objectsAtIndexes([1,3,5]) produces the error "Value of type '[Int]' has no member 'objectsAtIndexes'

import Foundation

var arr = [Int](6..<19)
let b = arr.objectsAtIndexes([1,3,5])
b = b.append(1)

extension Array {
    func objectsAtIndexes(indexes: [Int]) -> [Element] {
        var returnArray = [Element]()
        for i in indexes {
            returnArray.append(self[i])
        }
        return returnArray
    }
}

Answer 1

Just use that extension below the extension declaration this way:

import Foundation

extension Array {
    func objectsAtIndexes(indexes: [Int]) -> [Element] {
        var returnArray = [Element]()
        for i in indexes {
            returnArray.append(self[i])
        }
        return returnArray
    }
}

var arr = [Int](6..<19)
var b = arr.objectsAtIndexes([1,3,5])
b = b.append(1)

And replace this line:

b = b.append(1)

With this line:

b.append(1)

And your result will be: