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

大多数这些答案都假设输入包含一个空格，而不是空白，并且只有一个空格。如果你能安全地做出这样的假设，那么（来自bennett的）公认的答案是相当优雅的，也是我在可能的时候会采用的方法。

当我们无法做出这一假设时，一个更稳健的解决方案需要涵盖以下大多数答案没有考虑的情况：

制表符/换行符/空格（空白），包括重复出现的字符前导/尾随空格Apple/Linux（\n）和Windows（\r\n）换行符

为了涵盖这些情况，此解决方案使用正则表达式将所有空格（包括重复出现的字符和Windows换行符）转换为单个空格，然后修剪，然后拆分为单个空格：

斯威夫特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"]

假设您有一个名为“Hello World”的变量，如果您想将其拆分并存储为两个不同的变量，可以这样使用：

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

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

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))

Swift 4使拆分字符变得更加容易，只需为字符串使用新的拆分函数即可。

例子：让s=“嗨，你好”让a=s.split（分隔符：“，”）打印（a）

现在您得到了一个带有“hi”和“hello”的数组。