把一个字符串分割成一个数组

Say I have a string here:

var fullName: String = "First Last"

I want to split the string base on white space and assign the values to their respective variables

var fullNameArr = // something like: fullName.explode(" ") 

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

Also, sometimes users might not have a last name.

The Swift way is to use the global split function, like so:

var fullName = "First Last"
var fullNameArr = split(fullName) {$0 == " "}
var firstName: String = fullNameArr[0]
var lastName: String? = fullNameArr.count > 1 ? fullNameArr[1] : nil

with Swift 2

In Swift 2 the use of split becomes a bit more complicated due to the introduction of the internal CharacterView type. This means that String no longer adopts the SequenceType or CollectionType protocols and you must instead use the .characters property to access a CharacterView type representation of a String instance. (Note: CharacterView does adopt SequenceType and CollectionType protocols).

let fullName = "First Last"
let fullNameArr = fullName.characters.split{$0 == " "}.map(String.init)
// or simply:
// let fullNameArr = fullName.characters.split{" "}.map(String.init)

fullNameArr[0] // First
fullNameArr[1] // Last 

The easiest method to do this is by using componentsSeparatedBy:

For Swift 2:

import Foundation
let fullName : String = "First Last";
let fullNameArr : [String] = fullName.componentsSeparatedByString(" ")

// And then to access the individual words:

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

For Swift 3:

import Foundation

let fullName : String = "First Last"
let fullNameArr : [String] = fullName.components(separatedBy: " ")

// And then to access the individual words:

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

Just call componentsSeparatedByString method on your fullName

import Foundation

var fullName: String = "First Last"
let fullNameArr = fullName.componentsSeparatedByString(" ")

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

Update for Swift 3+

import Foundation

let fullName    = "First Last"
let fullNameArr = fullName.components(separatedBy: " ")

let name    = fullNameArr[0]
let surname = fullNameArr[1]

As an alternative to WMios's answer, you can also use componentsSeparatedByCharactersInSet, which can be handy in the case you have more separators (blank space, comma, etc.).

With your specific input:

let separators = NSCharacterSet(charactersInString: " ")
var fullName: String = "First Last";
var words = fullName.componentsSeparatedByCharactersInSet(separators)

// words contains ["First", "Last"]

Using multiple separators:

let separators = NSCharacterSet(charactersInString: " ,")
var fullName: String = "Last, First Middle";
var words = fullName.componentsSeparatedByCharactersInSet(separators)

// words contains ["Last", "First", "Middle"]

Xcode 9 Swift 4 or Xcode 8.2.1 • Swift 3.0.2

If you just need to properly format a person name, you can use PersonNameComponentsFormatter.

The PersonNameComponentsFormatter class provides localized representations of the components of a person’s name, as represented by a PersonNameComponents object. Use this class to create localized names when displaying person name information to the user.

// iOS (9.0 and later), macOS (10.11 and later), tvOS (9.0 and later), watchOS (2.0 and later)
let nameFormatter = PersonNameComponentsFormatter()

let name =  "Mr. Steven Paul Jobs Jr."
// personNameComponents requires iOS (10.0 and later)
if let nameComps  = nameFormatter.personNameComponents(from: name) {
    nameComps.namePrefix   // Mr.
    nameComps.givenName    // Steven
    nameComps.middleName   // Paul
    nameComps.familyName   // Jobs
    nameComps.nameSuffix   // Jr.

    // It can also be convufgured to format your names
    // Default (same as medium), short, long or abbreviated

    nameFormatter.style = .default
    nameFormatter.string(from: nameComps)   // "Steven Jobs"

    nameFormatter.style = .short
    nameFormatter.string(from: nameComps)   // "Steven"

    nameFormatter.style = .long
    nameFormatter.string(from: nameComps)   // "Mr. Steven Paul Jobs jr."

    nameFormatter.style = .abbreviated
    nameFormatter.string(from: nameComps)   // SJ

    // It can also be use to return an attributed string using annotatedString method
    nameFormatter.style = .long
    nameFormatter.annotatedString(from: nameComps)   // "Mr. Steven Paul Jobs jr."
}

I found an Interesting case, that

method 1

var data:[String] = split( featureData ) { $0 == "\u{003B}" }

When I used this command to split some symbol from the data that loaded from server, it can split while test in simulator and sync with test device, but it won't split in publish app, and Ad Hoc

It take me a lot of time to track this error, It might cursed from some Swift Version, or some iOS Version or neither

It's not about the HTML code also, since I try to stringByRemovingPercentEncoding and it's still not work

addition 10/10/2015

in Swift 2.0 this method has been changed to

var data:[String] = featureData.split {$0 == "\u{003B}"}

method 2

var data:[String] = featureData.componentsSeparatedByString("\u{003B}")

When I used this command, it can split the same data that load from server correctly

Conclusion, I really suggest to use the method 2

string.componentsSeparatedByString("")

This has Changed again in Beta 5. Weee! It's now a method on CollectionType

Old:

var fullName = "First Last"
var fullNameArr = split(fullName) {$0 == " "}

New:

var fullName = "First Last"
var fullNameArr = fullName.split {$0 == " "}

Apples Release Notes

Or without closures you can do just this in Swift 2:

let fullName = "First Last"
let fullNameArr = fullName.characters.split(" ")
let firstName = String(fullNameArr[0])

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]

The whitespace issue

Generally, people reinvent this problem and bad solutions over and over. Is this a space? " " and what about "\n", "\t" or some unicode whitespace character that you've never seen, in no small part because it is invisible. While you can get away with

A weak solution

import Foundation
let pieces = "Mary had little lamb".componentsSeparatedByString(" ")

If you ever need to shake your grip on reality watch a WWDC video on strings or dates. In short, it is almost always better to allow Apple to solve this kind of mundane task.

Robust Solution: Use NSCharacterSet

The way to do this correctly, IMHO, is to use NSCharacterSet since as stated earlier your whitespace might not be what you expect and Apple has provided a whitespace character set. To explore the various provided character sets check out Apple's NSCharacterSet developer documentation and then, only then, augment or construct a new character set if it doesn't fit your needs.

NSCharacterSet whitespaces

Returns a character set containing the characters in Unicode General Category Zs and CHARACTER TABULATION (U+0009).

let longerString: String = "This is a test of the character set splitting system"
let components = longerString.components(separatedBy: .whitespaces)
print(components)

let str = "one two"
let strSplit = str.characters.split(" ").map(String.init) // returns ["one", "two"]

Xcode 7.2 (7C68)

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. :)

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", "--"]

Swift 2.2 Error Handling & capitalizedString Added :

func setFullName(fullName: String) {
    var fullNameComponents = fullName.componentsSeparatedByString(" ")

    self.fname = fullNameComponents.count > 0 ? fullNameComponents[0]: ""
    self.sname = fullNameComponents.count > 1 ? fullNameComponents[1]: ""

    self.fname = self.fname!.capitalizedString
    self.sname = self.sname!.capitalizedString
}

Most of these answers assume the input contains a space - not whitespace, and a single space at that. If you can safely make that assumption, then the accepted answer (from bennett) is quite elegant and also the method I'll be going with when I can.

When we can't make that assumption, a more robust solution needs to cover the following siutations that most answers here don't consider:

• tabs/newlines/spaces (whitespace), including recurring characters
• leading/trailing whitespace
• Apple/Linux (\n) and Windows (\r\n) newline characters

To cover these cases this solution uses regex to convert all whitespace (including recurring and Windows newline characters) to a single space, trims, then splits by a single space:

Swift 3:

let searchInput = "  First \r\n \n \t\t\tMiddle    Last "
let searchTerms = searchInput 
    .replacingOccurrences(
        of: "\\s+",
        with: " ",
        options: .regularExpression
    )
    .trimmingCharacters(in: .whitespaces)
    .components(separatedBy: " ")

// searchTerms == ["First", "Middle", "Last"]

Xcode 8.0 / Swift 3

let fullName = "First Last"
var fullNameArr = fullName.components(separatedBy: " ")

var firstname = fullNameArr[0] // First
var lastname = fullNameArr[1] // Last

Long Way:

var fullName: String = "First Last"
fullName += " " // this will help to see the last word

var newElement = "" //Empty String
var fullNameArr = [String]() //Empty Array

for Character in fullName.characters {
    if Character == " " {
        fullNameArr.append(newElement)
        newElement = ""
    } else {
        newElement += "\(Character)"
    }
}


var firsName = fullNameArr[0] // First
var lastName = fullNameArr[1] // Last

Swift Dev. 4.0 (May 24, 2017)

A new function split in Swift 4 (Beta).

import Foundation
let sayHello = "Hello Swift 4 2017";
let result = sayHello.split(separator: " ")
print(result)

Output:

["Hello", "Swift", "4", "2017"]

Accessing values:

print(result[0]) // Hello
print(result[1]) // Swift
print(result[2]) // 4
print(result[3]) // 2017

Xcode 8.1 / Swift 3.0.1

Here is the way multiple delimiters with array.

import Foundation
let mathString: String = "12-37*2/5"
let numbers = mathString.components(separatedBy: ["-", "*", "/"])
print(numbers)

Output:

["12", "37", "2", "5"]

I had a scenario where multiple control characters can be present in the string I want to split. Rather than maintain an array of these, I just let Apple handle that part.

The following works with Swift 3.0.1 on iOS 10:

let myArray = myString.components(separatedBy: .controlCharacters)

String handling is still a challenge in Swift and it keeps changing significantly, as you can see from other answers. Hopefully things settle down and it gets simpler. This is the way to do it with the current 3.0 version of Swift with multiple separator characters.

Swift 3:

let chars = CharacterSet(charactersIn: ".,; -")
let split = phrase.components(separatedBy: chars)

// Or if the enums do what you want, these are preferred. 
let chars2 = CharacterSet.alphaNumerics // .whitespaces, .punctuation, .capitalizedLetters etc
let split2 = phrase.components(separatedBy: chars2)

Swift 4 makes it much easier to split characters, just use the new split function for Strings.

Example: let s = "hi, hello" let a = s.split(separator: ",") print(a)

Now you got an array with 'hi' and ' hello'.

Swift 4

let words = "these words will be elements in an array".components(separatedBy: " ")

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)
}

Swift 3

let line = "AAA    BBB\t CCC"
let fields = line.components(separatedBy: .whitespaces).filter {!$0.isEmpty}

• Returns three strings AAA, BBB and CCC
• Filters out empty fields
• Handles multiple spaces and tabulation characters
• If you want to handle new lines, then replace .whitespaces with .whitespacesAndNewlines

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"

Hope this is helpfull

Swift 4: Split a String into an array. Step 1: assign string. step 2: based on @ spliting. Note: variableName.components(separatedBy: "split keyword")

let fullName: String = "First Last @ triggerd event of the session by session storage @ it can be divided by the event of the trigger."
let fullNameArr = fullName.components(separatedBy: "@")
print("split", fullNameArr)

Let's say you have a variable named "Hello World" and if you want to split it and store it into two different variables you can use like this:

var fullText = "Hello World"
let firstWord = fullText.text?.components(separatedBy: " ").first
let lastWord = fullText.text?.components(separatedBy: " ").last

Swift 4

let string = "loremipsum.dolorsant.amet:"

let result = string.components(separatedBy: ".")

print(result[0])
print(result[1])
print(result[2])
print("total: \(result.count)")

Output

loremipsum
dolorsant
amet:
total: 3

Swift 4, Xcode 10 and iOS 12 Update 100% working

let fullName = "First Last"    
let fullNameArr = fullName.components(separatedBy: " ")
let firstName = fullNameArr[0] //First
let lastName = fullnameArr[1] //Last

See the Apple's documentation here for further information.

I was looking for loosy split, such as PHP's explode where empty sequences are included in resulting array, this worked for me:

"First ".split(separator: " ", maxSplits: 1, omittingEmptySubsequences: false)

Output:

["First", ""]

In Swift 4.1 and Xcode 9.4.1

//This is your str
let str = "This is my String" //Here replace with your string

Option 1

let items = str.components(separatedBy: " ")//Here replase space with your value and result is Array.
//Direct line of code
//let items = "This is my String".components(separatedBy: " ")
let str1 = items[0]
let str2 = items[1]
let str3 = items[2]
let str4 = items[3]
//OutPut
print(items.count)
print(str1)
print(str2)
print(str3)
print(str4)
print(items.first!)
print(items.last!)

Option 2

let items = str.split(separator: " ")
let str1 = String(items.first!)
let str2 = String(items.last!)
//Output
print(items.count)
print(items)
print(str1)
print(str2)

Option 3

let arr = str.split {$0 == " "}
print(arr)

Option 4

By Apple Documentation....

let line = "BLANCHE:   I don't want realism. I want magic!"
print(line.split(separator: " "))
print(line.split(separator: " ", maxSplits: 1))//This can split your string into 2 parts
print(line.split(separator: " ", maxSplits: 2))//This can split your string into 3 parts
print(line.split(separator: " ", omittingEmptySubsequences: false))//array contains empty strings where spaces were repeated.
print(line.split(separator: " ", omittingEmptySubsequences: true))//array not contains empty strings where spaces were repeated.
print(line.split(separator: " ", maxSplits: 4, omittingEmptySubsequences: false))
print(line.split(separator: " ", maxSplits: 3, omittingEmptySubsequences: true))