Split a String into an array in Swift?

Do not use whitespace to separate words. It will not work well for English. And it will not work at all for languages like Japanese or Chinese.

Here is a sample for tokenizing names from a given string:

import NaturalLanguage

actor Tokenizer {
    private let tagger = NLTagger(tagSchemes: [.nameType])

    func tokens(for text: String) async -> [String] {
        tagger.string = text

        let tags = tagger.tags(
            in: text.startIndex ..< text.endIndex,
            unit: .word,
            scheme: .nameType,
            options: [
                .omitPunctuation,
                .omitWhitespace,
                .joinNames,
            ]
        )

        return tags.map { String(text[$1]) }
    }
}

For swift 2, XCode 7.1:

let complete_string:String = "Hello world"
let string_arr =  complete_string.characters.split {$0 == " "}.map(String.init)
let hello:String = string_arr[0]
let world:String = string_arr[1]

Here is an algorithm I just build, which will split a String by any Character from the array and if there is any desire to keep the substrings with splitted characters one could set the swallow parameter to true.

Xcode 7.3 - Swift 2.2:

extension String {

    func splitBy(characters: [Character], swallow: Bool = false) -> [String] {

        var substring = ""
        var array = [String]()
        var index = 0

        for character in self.characters {

            if let lastCharacter = substring.characters.last {

                // swallow same characters
                if lastCharacter == character {

                    substring.append(character)

                } else {

                    var shouldSplit = false

                    // check if we need to split already
                    for splitCharacter in characters {
                        // slit if the last character is from split characters or the current one
                        if character == splitCharacter || lastCharacter == splitCharacter {

                            shouldSplit = true
                            break
                        }
                    }

                    if shouldSplit {

                        array.append(substring)
                        substring = String(character)

                    } else /* swallow characters that do not equal any of the split characters */ {

                        substring.append(character)
                    }
                }
            } else /* should be the first iteration */ {

                substring.append(character)
            }

            index += 1

            // add last substring to the array
            if index == self.characters.count {

                array.append(substring)
            }
        }

        return array.filter {

            if swallow {

                return true

            } else {

                for splitCharacter in characters {

                    if $0.characters.contains(splitCharacter) {

                        return false
                    }
                }
                return true
            }
        }
    }
}

Example:

"test text".splitBy([" "]) // ["test", "text"]
"test++text--".splitBy(["+", "-"], swallow: true) // ["test", "++" "text", "--"]

Simple way to split a string into array

var fullName: String = "First Last";

var fullNameArr = fullName.componentsSeparatedByString(" ")

var firstName: String = fullNameArr[0]
var lastName: String = fullNameArr[1]

As per Swift 2.2

You just write 2 line code and you will get the split string.

let fullName = "FirstName LastName"
var splitedFullName = fullName.componentsSeparatedByString(" ")
print(splitedFullName[0])
print(splitedFullName[1]) 

Enjoy. :)

I haven't found the solution that would handle names with 3 or more components and support older iOS versions.

struct NameComponentsSplitter {

    static func split(fullName: String) -> (String?, String?) {
        guard !fullName.isEmpty else {
            return (nil, nil)
        }
        let components = fullName.components(separatedBy: .whitespacesAndNewlines)
        let lastName = components.last
        let firstName = components.dropLast().joined(separator: " ")
        return (firstName.isEmpty ? nil : firstName, lastName)
    }
}

Passed test cases:

func testThatItHandlesTwoComponents() {
    let (firstName, lastName) = NameComponentsSplitter.split(fullName: "John Smith")
    XCTAssertEqual(firstName, "John")
    XCTAssertEqual(lastName, "Smith")
}

func testThatItHandlesMoreThanTwoComponents() {
    var (firstName, lastName) = NameComponentsSplitter.split(fullName: "John Clark Smith")
    XCTAssertEqual(firstName, "John Clark")
    XCTAssertEqual(lastName, "Smith")

    (firstName, lastName) = NameComponentsSplitter.split(fullName: "John Clark Jr. Smith")
    XCTAssertEqual(firstName, "John Clark Jr.")
    XCTAssertEqual(lastName, "Smith")
}

func testThatItHandlesEmptyInput() {
    let (firstName, lastName) = NameComponentsSplitter.split(fullName: "")
    XCTAssertEqual(firstName, nil)
    XCTAssertEqual(lastName, nil)
}

let fullName : String = "Steve.Jobs"
let fullNameArr : [String] = fullName.components(separatedBy: ".")

var firstName : String = fullNameArr[0]
var lastName : String = fullNameArr[1]

var fullName = "James Keagan Michael"
let first = fullName.components(separatedBy: " ").first?.isEmpty == false ? fullName.components(separatedBy: " ").first! : "John"
let last =  fullName.components(separatedBy: " ").last?.isEmpty == false && fullName.components(separatedBy: " ").last != fullName.components(separatedBy: " ").first ? fullName.components(separatedBy: " ").last! : "Doe"

• Disallow same first and last name
• If a fullname is invalid, take placeholder value "John Doe"

Expounding off of Don Vaughn's Answer, I liked the use of Regular Expressions. I'm surprised that this is only the 2nd Regex answer. However, if we could solve this in just one split method, instead of multiple methods, that would be great.

I was also inspired by Mithra Singam's Answer to exclude all punctuation as well as whitespace. However, having to create a list of disallowed characters didn't vibe with me.

• \w - Regular Expression for a Letter or Number symbol. No punctuation.

let foo = "(..#   Hello,,(---- World   ".split {
    String($0).range(of: #"\w"#, options: .regularExpression) == nil
}
print(foo) // Prints "Hello World"

Let's say you aren't comfortable will all of Unicode. How about just ASKII Letters and Numbers?

let bar = "(..#   Hello,,(---- World   ".split {
    !($0.isASCII && ($0.isLetter || $0.isNumber))
}
print(bar) // Prints "Hello World"

You can use this common function and add any string which you want to separate

func separateByString(String wholeString: String, byChar char:String) -> [String] {

    let resultArray = wholeString.components(separatedBy: char)
    return resultArray
}

var fullName: String = "First Last"
let array = separateByString(String: fullName, byChar: " ")
var firstName: String = array[0]
var lastName: String = array[1]
print(firstName)
print(lastName)

This is for String and CSV file for swift 4.2 at 20181206 1610

var dataArray : [[String]] = []
 let path = Bundle.main.path(forResource: "csvfilename", ofType: "csv")
        let url = URL(fileURLWithPath: path!)
        do {
            let data = try Data(contentsOf: url) 
            let content = String(data: data, encoding: .utf8)
            let parsedCSV = content?.components(separatedBy: "\r\n").map{ $0.components(separatedBy: ";") }
           for line in parsedCSV!
            {
                dataArray.append(line)
           }
        }
        catch let jsonErr {
            print("\n   Error read CSV file: \n ", jsonErr)
        }

            print("\n MohNada 20181206 1610 - The final result is \(dataArray)  \n ")