这在Beta 5中再次发生了变化。哭泣！它现在是CollectionType上的一个方法

旧版本：

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

新建：

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

苹果发行说明

最简单的方法是使用组件SeparatedBy:

对于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]

对于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]

Xcode 8.0/Swift 3

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

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

漫长的道路：

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

我还没有找到能够处理3个或更多组件名称并支持较旧iOS版本的解决方案。

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)
    }
}

通过测试用例：

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)
}

字符串处理在Swift中仍然是一个挑战，而且它一直在显著变化，从其他答案中可以看到。希望事情稳定下来，事情会变得更简单。这是在当前3.0版本的Swift中使用多个分隔符的方法。

斯威夫特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)

只需在fullName上调用componentsSeparatedByString方法

import Foundation

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

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

Swift 3更新+

import Foundation

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

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