如何在Swift中按空格拆分字符串

Question

let string = "hello hi"
var hello = ""
var hi = ""

我想要分割字符串，以便将 hello 的值变为 "hello"，将 hi 的值变为 "hi"。

- Clément Bisaillon

Answer 1

试试这个：

var myString: String = "hello hi";
var myStringArr = myString.componentsSeparatedByString(" ")

myString 是你的字符串的名称，myStringArr 包含由空格分隔的组件。

那么你可以按以下方式获取组件：

var hello: String = myStringArr [0]
var hi: String = myStringArr [1]

文档：componentsSeparatedByString

编辑：对于Swift 3，以上内容应为：

var myStringArr = myString.components(separatedBy: " ")

Doc: components(separatedBy:)

- JosEduSol

---

很棒的答案。最简单的方式。 - Mehmet

以上在Swift 3中已经发生了变化，现在是：'var arrayOfSeperatedParts = myOriginalString.components(separatedBy: "insertSeperatorHere")' - Dave G

杰出的...... - M Hamayun zeb

Answer 2

这里有一个split函数，它接收正则表达式，您可以定义扩展以备将来使用:

Swift 4

extension String {

    func split(regex pattern: String) -> [String] {

        guard let re = try? NSRegularExpression(pattern: pattern, options: [])
            else { return [] }

        let nsString = self as NSString // needed for range compatibility
        let stop = "<SomeStringThatYouDoNotExpectToOccurInSelf>"
        let modifiedString = re.stringByReplacingMatches(
            in: self,
            options: [],
            range: NSRange(location: 0, length: nsString.length),
            withTemplate: stop)
        return modifiedString.components(separatedBy: stop)
    }
}

例子：

let string1 = "hello world"
string1.split(regex: " ")    // ["hello", "world"]

let string2 = "hello    world"
string2.split(regex: "[ ]+")  // ["hello", "world"]

Swift 2.2

extension String {

    func split(regex pattern: String) -> [String] {

        guard let re = try? NSRegularExpression(pattern: pattern, options: []) 
            else { return [] }

        let nsString = self as NSString // needed for range compatibility
        let stop = "<SomeStringThatYouDoNotExpectToOccurInSelf>"
        let modifiedString = re.stringByReplacingMatchesInString(
            self,
            options: [],
            range: NSRange(location: 0, length: nsString.length),
            withTemplate: stop)
        return modifiedString.componentsSeparatedByString(stop)
    }
}

Swift 2.0

extension String {

    // java, javascript, PHP use 'split' name, why not in Swift? :)
    func split(regex: String) -> Array<String> {
        do{
            let regEx = try NSRegularExpression(pattern: regex, options: NSRegularExpressionOptions())
            let stop = "<SomeStringThatYouDoNotExpectToOccurInSelf>"
            let nsString = self as NSString // needed for range compatibility
            let modifiedString = regEx.stringByReplacingMatchesInString (self, options: NSMatchingOptions(), range: NSRange(location: 0, length: nsString.length), withTemplate:stop)
            return modifiedString.componentsSeparatedByString(stop)
        } catch {
            return []
        }
    }
}

Swift 1.1

extension String {

    // java, javascript, PHP use 'split' name, why not in Swift? :)
    func split(splitter: String) -> Array<String> {
        let regEx = NSRegularExpression(pattern: splitter, options: NSRegularExpressionOptions(), error: nil)
        let stop = "<SomeStringThatYouDoNotExpectToOccurInSelf>"
        let modifiedString = regEx.stringByReplacingMatchesInString (self, options: NSMatchingOptions(),
            range: NSMakeRange(0, countElements(self)),
            withTemplate:stop)
        return modifiedString.componentsSeparatedByString(stop)
    }
}

示例:

let string1 = "hello world"

string1.split(" ")    // ["hello", "world"]

let string2 = "hello    world"

string2.split("[ ]+")  // ["hello", "world"]

- Maxim Shoustin

---

请描述 @downvoter。 - Maxim Shoustin

我没有给它点踩。我知道这种方法的缺点：你无法确定参数是普通字符串还是正则表达式模式字符串。比如，如果我想按"\d+"（字面字符串，而不是正则表达式）来分割一个字符串，该怎么办呢？ - Tyler Liu

@TylerLong 这个方法告诉你它是一个正则表达式。如果你想按照字面意义 "\d+" 进行分割，那么你需要传入一个描述该字面字符串的正则表达式。例如："\\\\d\\+"。 - masukomi

我建议将该方法重命名为func split(regex pattern: String) -> [String]，这样在调用时就可以写成string1.split(regex: " ")。("pattern"是因为regex应该是NSRegularExpression)现有的CollectionType.split也可以接受单个字符，所以当参数仅为" "时很难确定调用哪一个。 - ctietze