Swift Text File To Array of Strings

Question

I was wondering what the simplest and cleanest to read a text file into an array of strings is in swift.

Text file:

line 1
line 2
line 3 
line 4

Into an array like this:

var array = ["line 1","line 2","line 3","line 4"]

I would also like to know how to do a similar thing into struct like this:

Struct struct{
   var name: String!
   var email: String!
}

so take a text file and put it into struct's in an array.

Thanks for the help!

http://stackoverflow.com/questions/24097826/read-and-write-data-from-text-file — brimstone, Mar 23 '15 at 18:22
See this post for an excellent discussion on the options for converting a text file to a line array. http://codereview.stackexchange.com/a/100813/79551 — Suragch, Aug 15 '15 at 02:28

score 17 · Answer 1 · edited Jan 17 '17 at 07:00

17

Updated for Swift 3

    var arrayOfStrings: [String]?

    do {
        // This solution assumes  you've got the file in your bundle
        if let path = Bundle.main.path(forResource: "YourTextFilename", ofType: "txt"){
            let data = try String(contentsOfFile:path, encoding: String.Encoding.utf8)                
            arrayOfStrings = data.components(separatedBy: "\n")
            print(arrayOfStrings)
        }
    } catch let err as NSError {
        // do something with Error
        print(err)
    }

edited Jan 17 '17 at 07:00

He Yifei 何一非

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answered Jul 06 '16 at 13:12

Adrian

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is there a version for swift5 out there somewhere? :) – esaruoho May 25 '19 at 10:30

score 15 · Accepted Answer · answered Mar 23 '15 at 18:46

15

First you must read the file:

let text = String(contentsOfFile: someFile, encoding: NSUTF8StringEncoding, error: nil)

Then you separate it by line using the componentsSeparatedByString method:

let lines : [String] = text.componentsSeparatedByString("\n")

answered Mar 23 '15 at 18:46

Ian

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2

Note that some files do not just `\n` as the new line marker. You can consider using `NSCharacterSet.newlineCharacterSet()` and `componentsSeparatedByCharactersInSet`. – Suragch Aug 15 '15 at 02:26
1

new Swift syntax would be: `try! let text = String(contentsOfFile: someFile!, encoding: NSUTF8StringEncoding)` http://stackoverflow.com/questions/32663872/swift2-cannot-invoke-initializer-for-type-nsstring – thumbtackthief Oct 17 '15 at 19:49

Cristian · Answer 3 · 2019-05-28T21:57:18.233

7

Updated for Swift 5:

The const path contains the file path.

do {
    let path: String = "file.txt"
    let file = try String(contentsOfFile: path)
    let text: [String] = file.components(separatedBy: "\n")
} catch let error {
    Swift.print("Fatal Error: \(error.localizedDescription)")
}

If you want to print what's inside of file.txt line by line:

for line in text {
    Swift.print(line)
}

edited May 28 '19 at 21:57

answered Jul 24 '17 at 14:16

Cristian

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is there a version for swift5 out there somewhere? :) – esaruoho May 25 '19 at 10:29
thanks muchly! :) and how would i be able to output that content into an Array? (one textfile, one Array) – esaruoho May 29 '19 at 07:31

score 2 · Answer 4 · edited Mar 23 '15 at 18:38

2

Here is a way to convert a string to an array(Once you read in the text):

var myString = "Here is my string"

var myArray : [String] = myString.componentsSeparatedByString(" ")

This returns a string array with the following values: ["Here", "is", "my", "string"]

edited Mar 23 '15 at 18:38

ebo

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answered Mar 23 '15 at 18:30

tukbuk23

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score 2 · Answer 5 · edited Sep 10 '18 at 22:48

2

Swift 4:

do {
    let contents = try String(contentsOfFile: file, encoding: String.Encoding.utf8)
    let lines : [String] = contents.components(separatedBy: "\n")    
} catch let error as NSError {
    print(error.localizedDescription)
}

edited Sep 10 '18 at 22:48

pkamb

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answered Apr 04 '18 at 03:24

Jinesh Mathew

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is there a version for swift5 out there somewhere? :) – esaruoho May 25 '19 at 10:30

score 1 · Answer 6 · answered Aug 10 '17 at 15:30

1

In Swift 3 for me worked like below:

Import Foundation

let lines : [String] = contents.components(separatedBy: "\n")

answered Aug 10 '17 at 15:30

Alessandro Mattiuzzi

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Swift Text File To Array of Strings

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