set NSArray instance using reference in Swift

Question

I'm trying to set the values for NSArray using reference in Swift but can't seem to get it working.

var list = self.isFiltered ? self.filteredEventsList : self.eventsList
self.sortTableViewForEventName(&list)

Then:

private func sortTableViewForEventName(inout eventArray: NSArray) {

        let sortedEvents = eventArray.sortedArrayUsingComparator({ (firstEvent, secondEvent) in

            let firstEventName = (firstEvent as! Event).name
            let secondEventName = (secondEvent as! Event).name

            return firstEventName.compare(secondEventName)
        })

        eventArray = sortedEvents
    }

The change in eventArray does not reflect in eventsList or filteredEventsList, whichever may be applicable.

Answer 1

You need to have a really good reason for using inout parameters, and in this case I don't think you have one. You can simply have your function return the sorted array:

private func sortTableViewForEventName(eventArray: NSArray) -> NSArray {
    let sortedEvents = eventArray.sortedArrayUsingComparator({ (firstEvent, secondEvent) in

        let firstEventName = (firstEvent as! Event).name
        let secondEventName = (secondEvent as! Event).name

        return firstEventName.compare(secondEventName)
    })

    return sortedEvents
}

then you would say

var list = self.isFiltered ? self.filteredEventsList : self.eventsList
list = self.sortTableViewForEventName(list)

But, unless you have a good reason for using NSArray, you can just use a Swift array and gain type awareness/safety and more concise sorting:

private func sortTableViewForEventName(eventArray: [Event]) -> [Event] {
    let sortedEvents = eventArray.sort {
        $0.name < $1.name
    }
    return sortedEvents
 }