Sort NSArray of NSDecimalNumber

Question

NSDecimalNumber has a useful compare: method.

Rather then writing a wrapper around this compare method and then calling sortedArrayUsingFunction:context:, I would simply like to directly pass the NSDecimalNumber compare method to one of NSArray's sorted<...> methods.

What is the best way to do this using Swift?

Answer 1

For NSArray you can simply use sortedArrayUsingSelector() and pass the compare: method as selector:

let array = NSArray(objects:
        NSDecimalNumber(integer: 30),
        NSDecimalNumber(integer: 20),
        NSDecimalNumber(integer: 10))
let sorted = array.sortedArrayUsingSelector("compare:")
// Swift 2.2 or later:
let sorted = array.sortedArrayUsingSelector(#selector(NSNumber.compare(_:)))

print(sorted) // [10, 20, 30]