In this blog you can find both versions (Obj C & Swift) for converting NSData to NSString or vice-versa. For more details please visit the link http://findnerd.com/list/view/How-to-convert-NSData-to-NSString-or-vice-versa-in-Objective-C-and-Swift/4137/
How to convert NSData to NSString or vice versa in Objective C and Swift | Heykuki News