In this blog post, you will learn how to read and write a string into a text file in Swift.
In the code example below, we will first write a string value into a text file and then we will read the content of that text file to see if it contains the string we have written to it. So the code below includes two examples:
- How to write a string value into a file in Swift,
- How to read the content of a file in Swift
If you are interested in video lessons on how to write Unit tests and UI tests to test your Swift mobile app, check out this page: Unit Testing Swift Mobile App
Code Example
let fileName = "myFileName.txt" var filePath = "" // Fine documents directory on device let dirs : [String] = NSSearchPathForDirectoriesInDomains(FileManager.SearchPathDirectory.documentDirectory, FileManager.SearchPathDomainMask.allDomainsMask, true) if dirs.count > 0 { let dir = dirs[0] //documents directory filePath = dir.appending("/" + fileName) print("Local path = \(filePath)") } else { print("Could not find local directory to store file") return } // Set the contents let fileContentToWrite = "Text to be recorded into file" do { // Write contents to file try fileContentToWrite.write(toFile: filePath, atomically: false, encoding: String.Encoding.utf8) } catch let error as NSError { print("An error took place: \(error)") } // Read file content. Example in Swift do { // Read file content let contentFromFile = try NSString(contentsOfFile: filePath, encoding: String.Encoding.utf8.rawValue) print(contentFromFile) } catch let error as NSError { print("An error took place: \(error)") }
For more Swift code examples and tutorials, please check the Swift Code Examples page on this website.