Simple Way to Read Local File Using Swift

Simple way to read local file using Swift?

If you have a tilde in your path you can try this:

let location = "~/file.txt".stringByExpandingTildeInPath
let fileContent = NSString(contentsOfFile: location, encoding: NSUTF8StringEncoding, error: nil)

otherwise just use this:

let location = "/Users/you/Desktop/test.txt"
let fileContent = NSString(contentsOfFile: location, encoding: NSUTF8StringEncoding, error: nil)

This gives you a string representation of the file, which I assumed is what you want.
You can use NSData(contentsOfFile: location) to get a binary representation, but you would normally do that for, say, music files and not a text file.

Update: With Xcode 7 and Swift 2 this doesn't work anymore. You can now use

let location = NSString(string:"~/file.txt").stringByExpandingTildeInPath
let fileContent = try? NSString(contentsOfFile: location, encoding: NSUTF8StringEncoding)

Read Local Text File in Swift IOS

The following will place the contents of the file into a string:

let filePath = NSBundle.mainBundle().pathForResource("file", ofType: "txt");
let fileData = String(filePath!, encoding:NSUTF8StringEncoding, error:nil)!

Read and write a String from text file

For reading and writing you should use a location that is writeable, for example documents directory. The following code shows how to read and write a simple string. You can test it on a playground.

Swift 3.x - 5.x

let file = "file.txt" //this is the file. we will write to and read from it

let text = "some text" //just a text

if let dir = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first {

    let fileURL = dir.appendingPathComponent(file)

    //writing
    do {
        try text.write(to: fileURL, atomically: false, encoding: .utf8)
    }
    catch {/* error handling here */}

    //reading
    do {
        let text2 = try String(contentsOf: fileURL, encoding: .utf8)
    }
    catch {/* error handling here */}
}

Swift 2.2

let file = "file.txt" //this is the file. we will write to and read from it

let text = "some text" //just a text

if let dir = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.DocumentDirectory, NSSearchPathDomainMask.AllDomainsMask, true).first {
    let path = NSURL(fileURLWithPath: dir).URLByAppendingPathComponent(file)

    //writing
    do {
        try text.writeToURL(path, atomically: false, encoding: NSUTF8StringEncoding)
    }
    catch {/* error handling here */}

    //reading
    do {
        let text2 = try NSString(contentsOfURL: path, encoding: NSUTF8StringEncoding)
    }
    catch {/* error handling here */}
}

Swift 1.x

let file = "file.txt"

if let dirs : [String] = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.DocumentDirectory, NSSearchPathDomainMask.AllDomainsMask, true) as? [String] {
    let dir = dirs[0] //documents directory
    let path = dir.stringByAppendingPathComponent(file);
    let text = "some text"

    //writing
    text.writeToFile(path, atomically: false, encoding: NSUTF8StringEncoding, error: nil);

    //reading
    let text2 = String(contentsOfFile: path, encoding: NSUTF8StringEncoding, error: nil)
}

Read a text file line by line in Swift?

Swift 3.0

if let path = Bundle.main.path(forResource: "TextFile", ofType: "txt") {
    do {
        let data = try String(contentsOfFile: path, encoding: .utf8)
        let myStrings = data.components(separatedBy: .newlines)
        TextView.text = myStrings.joined(separator: ", ")
    } catch {
        print(error)
    }
}

The variable myStrings should be each line of the data.

The code used is from:
Reading file line by line in iOS SDK written in Obj-C and using NSString

Check edit history for previous versions of Swift.

How to read text-file in Swift 2.0 with one line of code

I've read about the advantages of Swift...If it's so new and powerful,
why would they make such a simple task so complicated?

Well, in Swift you can do this:

let string = try? NSString(contentsOfFile: "name.txt", encoding: NSASCIIStringEncoding)
print(string)

The question is if you really want to, because the longer versions give you more flexibility and better error handling...

Reading in a JSON File Using Swift

Follow the below code :

if let path = NSBundle.mainBundle().pathForResource("test", ofType: "json")
{
    if let jsonData = NSData(contentsOfFile: path, options: .DataReadingMappedIfSafe, error: nil)
    {
        if let jsonResult: NSDictionary = NSJSONSerialization.JSONObjectWithData(jsonData, options: NSJSONReadingOptions.MutableContainers, error: nil) as? NSDictionary
        {
            if let persons : NSArray = jsonResult["person"] as? NSArray
            {
                // Do stuff
            }
        }
     }
}

The array "persons" will contain all data for key person. Iterate throughs to fetch it.

Swift 4.0:

if let path = Bundle.main.path(forResource: "test", ofType: "json") {
    do {
          let data = try Data(contentsOf: URL(fileURLWithPath: path), options: .mappedIfSafe)
          let jsonResult = try JSONSerialization.jsonObject(with: data, options: .mutableLeaves)
          if let jsonResult = jsonResult as? Dictionary<String, AnyObject>, let person = jsonResult["person"] as? [Any] {
                    // do stuff
          }
      } catch {
           // handle error
      }
}

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