If we have, for example, situation like this:
var myString = "Today was a good day" What is the best way to return the first word, which is "Today"? I think mapping should be applied, but not sure how.
Thanks.
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6 Answers
The simplest way I can think of is
Swift 3
let string = "hello world" let firstWord = string.components(separatedBy: " ").first Swift 2.2
let string = "hello world" let firstWord = string.componentsSeparatedByString(" ").first and if you think you need to use it a lot in your code, make it as an extension
extension String { func firstWord() -> String? { return self.components(separatedBy: " ").first } } Usage
let string = "hello world" let firstWord = string.firstWord() 
1 Comment
Code Roadie
Depending on the string, this might be too naive. E.g., "Hello, World!" would yield "Hello," which may or may not be what you wanted. Maybe try
let separators = " ,.;:*?" /* word boundaries */ let components = self.components(separatedBy: CharacterSet.init(charactersIn: separators) ) let firstWord = components.first?You can use StringProtocol method enumerateSubstrings(in: Range<String.Index>) with options .byWords to enumerate the words in your string and just get the first element:
Swift 5.1 • Xcode 11 or later
Note: For older Swift syntax check this post edit history
import Foundation extension StringProtocol { var byLines: [SubSequence] { components(separated: .byLines) } var byWords: [SubSequence] { components(separated: .byWords) } func components(separated options: String.EnumerationOptions)-> [SubSequence] { var components: [SubSequence] = [] enumerateSubstrings(in: startIndex..., options: options) { _, range, _, _ in components.append(self[range]) } return components } var firstWord: SubSequence? { var word: SubSequence? enumerateSubstrings(in: startIndex..., options: .byWords) { _, range, _, stop in word = self[range] stop = true } return word } var firstLine: SubSequence? { var line: SubSequence? enumerateSubstrings(in: startIndex..., options: .byLines) { _, range, _, stop in line = self[range] stop = true } return line } } Playground Testing:
let string = "• Today was a good day.\n• Tomorrow will be better.\n" let firstWord = string.firstWord // "Today" let firstLine = string.firstLine // "• Today was a good day." let firstLineLastWord = string.firstLine?.byWords.last // day let firstLineLast2Words = string.firstLine?.byWords.suffix(2) // ["good", "day"] Comments
I would prefer using CharacterSet, since words can be delimited by white-spaces as well as punctuation marks.
var myString = "Today was a good day" let nonLetters = CharacterSet.letters.inverted let first = myString.components(separatedBy: nonLetters).first 
Comments
Elegant solution:
extension String { var firstWord: String { self.components(separatedBy: " ").first ?? "" } } Usage:
let myString = "Today was a good day" print(myString.firstWord) output:
Today 
Comments
To avoid processing the whole string just to get the first word, you could do this:
let string = "Hello World" let word1 = string.prefix{ (c:Character) in CharacterSet.letters.contains(c.unicodeScalars.first!) } 9 Comments
Leo Dabus
Note that If you don't want to enumerate the whole string you can stop the enumeratedSubsrtrings in range after finding the first word.
Leo Dabus
Why not simply
prefix { $0 != " " }? If you are extra paranoid prefix { String($0).rangeOfCharacter(from: .whitespaces) == nil } or using the letters approach prefix { String($0).rangeOfCharacter(from: .letters) != nil } Note that all of this only work if the word is at the beginning of the string. try "•Sugar"
Alain T.
I wanted to make sure that any non-letter delimiter would be detected (not just spaces). Also, transforming each letter into a string for processing didn't seem as straightforward (or efficient) to me.
Leo Dabus
Using only the first Unicode value doesn't seem also correct
Alain T.
It would not work for composite unicode characters such as emojis but for all roman character sets it does work.
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Try using prefix() function
let string = "Today was a good day" if let spaceIndex = string.firstIndex(of: " ") { let firstWord = String(string.prefix(upTo: string.index(after: spaceIndex))) print(firstWord) // Today } 