是的，你可以这样做:

var str = "  this is the answer   "
str = str.trimmingCharacters(in: CharacterSet.whitespacesAndNewlines)
print(srt) // "this is the answer"

CharacterSet实际上是一个非常强大的工具，用于创建修剪规则，比. whitespacesandnewlines等预定义集更灵活。

例如:

var str = " Hello World !"
let cs = CharacterSet.init(charactersIn: " !")
str = str.trimmingCharacters(in: cs)
print(str) // "Hello World"

在Swift 3.0中

extension String
{   
    func trim() -> String
   {
    return self.trimmingCharacters(in: CharacterSet.whitespaces)
   }
}

你可以打电话

let result = " Hello World ".trim()  /* result = "Hello World" */

另一种类似的方式:

extension String {
    var trimmed:String {
        return self.trimmingCharacters(in: CharacterSet.whitespaces)
    }
}

使用:

let trimmedString = "myString ".trimmed

把这段代码放在你项目的一个文件中，比如Utils.swift:

extension String {   
    func trim() -> String {
        return self.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceCharacterSet())
    }
}

所以你可以这样做:

let result = " abc ".trim()
// result == "abc"

Swift 3.0解决方案

extension String {   
    func trim() -> String {
    return self.trimmingCharacters(in: NSCharacterSet.whitespaces)
   }
}

所以你可以这样做:

let result = " Hello World ".trim()
// result = "HelloWorld"

extension String {
    /// EZSE: Trims white space and new line characters
    public mutating func trim() {
         self = self.trimmed()
    }

    /// EZSE: Trims white space and new line characters, returns a new string
    public func trimmed() -> String {
        return self.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceAndNewlineCharacterSet())
    }
}

从我的这个回购:https://github.com/goktugyil/EZSwiftExtensions/commit/609fce34a41f98733f97dfd7b4c23b5d16416206

您还可以发送您想要修剪的字符

extension String {


    func trim() -> String {

        return self.trimmingCharacters(in: .whitespacesAndNewlines)

    }

    func trim(characterSet:CharacterSet) -> String {

        return self.trimmingCharacters(in: characterSet)

    }
}

validationMessage = validationMessage.trim(characterSet: CharacterSet(charactersIn: ","))