[iOS] Data Persistence

reference.swift

// ## NSUserDefaults

// Storing a value in NSUserDefaults
NSUserDefaults.standardUserDefaults().defaults.setFloat(22.5 forKey: “myValue”)

// Retrieving a value from NSUserDefaults
let value = NSUserDefaults.standardUserDefaults().floatForKey(“myValue”)

// ## File System

// Building the path for a file in the Documents directory
let filename = "usersVoice.wav"
let dirPath = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)[0] as! String
let pathArray = [dirPath, filename]
let fileURL =  NSURL.fileURLWithPathComponents(pathArray)!

// Checking to see if a file exists
if NSFileManager.defaultManager().fileExistsAtPath(audioFileURL().path!) {
    shouldSegueToSoundPlayer = true       
}