Swift 4、Xcode 10和iOS 12更新100%工作

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

有关更多信息，请参阅此处的Apple文档。

Swift 4或更高版本

如果您只需要正确设置人名格式，可以使用PersonNameComponentsFormater。

PersonNameComponentsFormater类提供本地化人名组成部分的表示通过PersonNameComponents对象。使用此类创建本地化当向用户显示人名信息时。

// 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 configured 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."
}

编辑/更新：

Swift 5或更高版本

对于按非字母字符拆分字符串，我们可以使用新的Character属性isLetter：

let fullName = "First Last"

let components = fullName.split{ !$0.isLetter }
print(components)  // "["First", "Last"]\n"

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

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

对于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]

您可以使用此公共函数并添加任何要分隔的字符串

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)

斯威夫特4

let string = "loremipsum.dolorsant.amet:"

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

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

输出

loremipsum
dolorsant
amet:
total: 3