Saving Data in iOS

In this challenge, you’ll learn about what’s happening behind the scenes when you save a String with its write method.

try string.write(to: <#T##URL#>, atomically: <#T##Bool#>, encoding: <#T##String.Encoding#>)

Here, you’ve got a method that creates a Data object out of a String using a “String Encoding”. Create a URL to save your string from the previous episode using this new method you just saw about, then read the saved String back!

Let’s go over the challenge. Regardless of the outcome, kudos to you for giving it a shot! Creating a URL for your file is something you have done a few times by now.

let catsURL = URL(fileURLWithPath: "Cats.txt", relativeTo: FileManager.documentsDirectoryURL)

How did you do with writing the string to a file, and the atomically parameter? In your apps, atomically is an important one; it allows you to write to a URL while avoiding potential file corruption.

…, atomically: true)

For reading the file back, I went with a String initializer.

let catsChallengeString = try String(contentsOf: catsURL)

Your sidebar should show that you’ve successfully read back your four cat emoji. Excellent!