快速解决方案:

用法:

let txt = "        hello world     "
let txt1 = txt.trimStart() // "hello world     "
let txt2 = txt.trimEnd()   // "        hello world"

用法二:

let txt = "rr rrr rrhello world r r r r r r"
let txt1 = txt.trimStart(["r", " "]) // "hello world r r r r r r"
let txt2 = txt.trimEnd(["r", " "])   // "rr rrr rrhello world"

如果你需要移除字符串中的所有空白:

txt.replace(of: " ", to: "")

public extension String {
    func trimStart(_ char: Character) -> String {
        return trimStart([char])
    }
    
    func trimStart(_ symbols: [Character] = [" ", "\t", "\r", "\n"]) -> String {
        var startIndex = 0
        
        for char in self {
            if symbols.contains(char) {
                startIndex += 1
            }
            else {
                break
            }
        }
        
        if startIndex == 0 {
            return self
        }
        
        return String( self.substring(from: startIndex) )
    }
    
    func trimEnd(_ char: Character) -> String {
        return trimEnd([char])
    }
    
    func trimEnd(_ symbols: [Character] = [" ", "\t", "\r", "\n"]) -> String {
        var endIndex = self.count - 1
        
        for i in (0...endIndex).reversed() {
            if symbols.contains( self[i] ) {
                endIndex -= 1
            }
            else {
                break
            }
        }
        
        if endIndex == self.count {
            return self
        }
        
        return String( self.substring(to: endIndex + 1) )
    }
}

/////////////////////////
/// ACCESS TO CHAR BY INDEX
////////////////////////
extension StringProtocol {
    subscript(offset: Int) -> Character { self[index(startIndex, offsetBy: offset)] }
    subscript(range: Range<Int>) -> SubSequence {
        let startIndex = index(self.startIndex, offsetBy: range.lowerBound)
        return self[startIndex..<index(startIndex, offsetBy: range.count)]
    }
    subscript(range: ClosedRange<Int>) -> SubSequence {
        let startIndex = index(self.startIndex, offsetBy: range.lowerBound)
        return self[startIndex..<index(startIndex, offsetBy: range.count)]
    }
    subscript(range: PartialRangeFrom<Int>) -> SubSequence { self[index(startIndex, offsetBy: range.lowerBound)...] }
    subscript(range: PartialRangeThrough<Int>) -> SubSequence { self[...index(startIndex, offsetBy: range.upperBound)] }
    subscript(range: PartialRangeUpTo<Int>) -> SubSequence { self[..<index(startIndex, offsetBy: range.upperBound)] }
}

好吧，这是老问题了，但我自己也遇到过这个问题，除了删除所有空白之外，上面的答案都不起作用，这可能会损害应用的功能。我的问题是这样的:

["This", " is", " my", " array", " it is awesome"]

如果修剪所有的空白，这将是输出:

["This", "is", "my", "array", "itisawesome"]

所以我需要消除前导间距，并简单地从:

 let array = jsonData.components(separatedBy: ",")

To

let array = jsonData.components(separatedBy: ", ")

修正了这个问题。希望将来有人发现这个有用。

在Swift 4修剪空白

let strFirstName = txtFirstName.text?.trimmingCharacters(in: 
 CharacterSet.whitespaces)

如果你想要从前面(和后面)而不是中间删除空格，你应该使用stringByTrimmingCharactersInSet

    let dirtyString   = " First Word "
    let cleanString = dirtyString.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceCharacterSet())

如果你想从字符串的任何地方删除空格，那么你可能需要查看stringbyreplacement…

快速解决方案:

用法:

let txt = "        hello world     "
let txt1 = txt.trimStart() // "hello world     "
let txt2 = txt.trimEnd()   // "        hello world"

用法二:

let txt = "rr rrr rrhello world r r r r r r"
let txt1 = txt.trimStart(["r", " "]) // "hello world r r r r r r"
let txt2 = txt.trimEnd(["r", " "])   // "rr rrr rrhello world"

如果你需要移除字符串中的所有空白:

txt.replace(of: " ", to: "")

public extension String {
    func trimStart(_ char: Character) -> String {
        return trimStart([char])
    }
    
    func trimStart(_ symbols: [Character] = [" ", "\t", "\r", "\n"]) -> String {
        var startIndex = 0
        
        for char in self {
            if symbols.contains(char) {
                startIndex += 1
            }
            else {
                break
            }
        }
        
        if startIndex == 0 {
            return self
        }
        
        return String( self.substring(from: startIndex) )
    }
    
    func trimEnd(_ char: Character) -> String {
        return trimEnd([char])
    }
    
    func trimEnd(_ symbols: [Character] = [" ", "\t", "\r", "\n"]) -> String {
        var endIndex = self.count - 1
        
        for i in (0...endIndex).reversed() {
            if symbols.contains( self[i] ) {
                endIndex -= 1
            }
            else {
                break
            }
        }
        
        if endIndex == self.count {
            return self
        }
        
        return String( self.substring(to: endIndex + 1) )
    }
}

/////////////////////////
/// ACCESS TO CHAR BY INDEX
////////////////////////
extension StringProtocol {
    subscript(offset: Int) -> Character { self[index(startIndex, offsetBy: offset)] }
    subscript(range: Range<Int>) -> SubSequence {
        let startIndex = index(self.startIndex, offsetBy: range.lowerBound)
        return self[startIndex..<index(startIndex, offsetBy: range.count)]
    }
    subscript(range: ClosedRange<Int>) -> SubSequence {
        let startIndex = index(self.startIndex, offsetBy: range.lowerBound)
        return self[startIndex..<index(startIndex, offsetBy: range.count)]
    }
    subscript(range: PartialRangeFrom<Int>) -> SubSequence { self[index(startIndex, offsetBy: range.lowerBound)...] }
    subscript(range: PartialRangeThrough<Int>) -> SubSequence { self[...index(startIndex, offsetBy: range.upperBound)] }
    subscript(range: PartialRangeUpTo<Int>) -> SubSequence { self[..<index(startIndex, offsetBy: range.upperBound)] }
}

Swift 3版本

  //This function trim only white space:
   func trim() -> String
        {
            return self.trimmingCharacters(in: CharacterSet.whitespaces)
        }
    //This function trim whitespeaces and new line that you enter:
     func trimWhiteSpaceAndNewLine() -> String
        {
            return self.trimmingCharacters(in: CharacterSet.whitespacesAndNewlines)
        }