Sorting of an array alphabetically in swift

First convert NSMutableArray to the Array by using below line of code.

let swiftArray = mutableArray as AnyObject as! [String]

Use below line of code to sort the Array.

var sortedArray = names.sorted { $0.localizedCaseInsensitiveCompare($1) == NSComparisonResult.OrderedAscending }

Check below link for sort Closures.
https://developer.apple.com/library/ios/documentation/Swift/Conceptual/Swift_Programming_Language/Closures.html

Update for Swift 3.0

var sortedArray = swiftArray.sorted { $0.localizedCaseInsensitiveCompare($1) == ComparisonResult.orderedAscending }