假设我这里有一个字符串：
var fullName: String = "First Last"
我想在空白处拆分字符串，并将值分配给它们各自的变量
var fullNameArr = // something like: fullName.explode(" ")
var firstName: String = fullNameArr[0]
var lastName: String? = fullnameArr[1]
此外，有时用户可能没有姓氏。
当前回答
作为WMios答案的替代方案，您还可以使用componentsSeparatedByCharactersSet，这在分隔符（空格、逗号等）较多的情况下非常方便。
使用您的特定输入：
let separators = NSCharacterSet(charactersInString: " ")
var fullName: String = "First Last";
var words = fullName.componentsSeparatedByCharactersInSet(separators)
// words contains ["First", "Last"]
使用多个分隔符：
let separators = NSCharacterSet(charactersInString: " ,")
var fullName: String = "Last, First Middle";
var words = fullName.componentsSeparatedByCharactersInSet(separators)
// words contains ["Last", "First", "Middle"]
其他回答
作为WMios答案的替代方案，您还可以使用componentsSeparatedByCharactersSet，这在分隔符（空格、逗号等）较多的情况下非常方便。
使用您的特定输入：
let separators = NSCharacterSet(charactersInString: " ")
var fullName: String = "First Last";
var words = fullName.componentsSeparatedByCharactersInSet(separators)
// words contains ["First", "Last"]
使用多个分隔符：
let separators = NSCharacterSet(charactersInString: " ,")
var fullName: String = "Last, First Middle";
var words = fullName.componentsSeparatedByCharactersInSet(separators)
// words contains ["Last", "First", "Middle"]
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
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"
不允许使用相同的名字和姓氏如果全名无效，则取占位符值“John Doe”
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", ""]
只有拆分才是正确的答案，这里有两个以上空格的差异。
雨燕5
var temp = "Hello world ni hao"
let arr = temp.components(separatedBy: .whitespacesAndNewlines)
// ["Hello", "world", "", "", "", "", "ni", "hao"]
let arr2 = temp.components(separatedBy: " ")
// ["Hello", "world", "", "", "", "", "ni", "hao"]
let arr3 = temp.split(whereSeparator: {$0 == " "})
// ["Hello", "world", "ni", "hao"]
