Read and Write String Into a Text File

In this code example 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 include two examples:

  • How to write a string value into a file in Swift
  • How to read content of a file in Swift
  
        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)")
        }

You can also store string values into NSUserDefaults. Have a look at this code example to learn how to write and read values of different data types from NSUserDefaults:

NSUserDefaults example in Swift


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