How to split a string by new lines in Swift

Question

I have a string that I got from a text file.

Text file:

Line 1
Line 2
Line 3
...

I want to convert it to an array, one array element p

Answer 1

Swift 5.2 or later

You can split your String using the new Character property isNewline:

let sentence = "Line 1\nLine 2\nLine 3\n"
let lines = sentence.split(whereSeparator: \.isNewline)
print(lines)   // "[Line 1, Line 2, Line 3]\n"

---

You can also extend StringProtocol and create a lines property to return break up the string lines into subsequences:

extension StringProtocol {
    var lines: [SubSequence] { split(whereSeparator: \.isNewline) }
}

---

let sentence = "Line 1\nLine 2\r\nLine 3\n"
for line in sentence.lines {
    print(line)
}
let lines = sentence.lines  // ["Line 1", "Line 2", "Line 3"]

---

---

Original Answer

You can use String method enumerateLines:

Enumerates all the lines in a string.

Swift 3 or later

let sentence = "Line 1\nLine 2\nLine 3\n"
var lines: [String] = []
sentence.enumerateLines { line, _ in
    lines.append(line)
}
print(lines)   // "[Line 1, Line 2, Line 3]"

---

extension String {
    var lines: [String] {
        var result: [String] = []
        enumerateLines { line, _ in result.append(line) }
        return result
    }
}

---

let sentence2 = "Line 4\nLine 5\nLine 6\n"
let sentence2Lines = sentence2.lines
print(sentence2Lines)    // ["Line 4", "Line 5", "Line 6"]
let sentence3 = "Line 7\r\nLine 8\r\nLine 9\r\n"
let sentence3Lines = sentence3.lines
print(sentence3Lines)  // "[Line 7, Line 8, Line 9]"