我在寻找loosy拆分，例如PHP的分解，其中空序列包含在结果数组中，这对我很有用：

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

输出：

["First", ""]

Swift的方法是使用全局拆分函数，如下所示：

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

使用Swift 2

在Swift 2中，由于引入了内部CharacterView类型，拆分的使用变得有点复杂。这意味着String不再采用SequenceType或CollectionType协议，您必须改为使用.characts属性来访问String实例的CharacterView类型表示。（注意：CharacterView确实采用SequenceType和CollectionType协议）。

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 

这里是我刚刚构建的一个算法，它将通过数组中的任何字符分割字符串，如果有任何希望保留具有分割字符的子字符串，可以将swall参数设置为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
            }
        }
    }
}

例子：

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

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)

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]

在Swift 4.2和Xcode 10中

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

选项1

let items = str.components(separatedBy: " ")//Here replase space with your value and the result is Array.
//Direct single 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!)

选项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)

选项3

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

选项4

let line = "BLANCHE:   I don't want realism. I want magic!"
print(line.split(separator: " "))
// Prints "["BLANCHE:", "I", "don\'t", "want", "realism.", "I", "want", "magic!"]"

通过Apple文档。。。。

let line = "BLANCHE:   I don't want realism. I want magic!"
print(line.split(separator: " "))
// Prints "["BLANCHE:", "I", "don\'t", "want", "realism.", "I", "want", "magic!"]"

print(line.split(separator: " ", maxSplits: 1))//This can split your string into 2 parts
// Prints "["BLANCHE:", "  I don\'t want realism. I want magic!"]"

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.
// Prints "["BLANCHE:", "", "", "I", "don\'t", "want", "realism.", "I", "want", "magic!"]"

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))