这个String扩展删除了字符串中的所有空格，而不仅仅是尾随空格…

 extension String {
    func replace(string:String, replacement:String) -> String {
        return self.replacingOccurrences(of: string, with: replacement, options: NSString.CompareOptions.literal, range: nil)
    }

    func removeWhitespace() -> String {
        return self.replace(string: " ", replacement: "")
    }
  }

例子:

let string = "The quick brown dog jumps over the foxy lady."
let result = string.removeWhitespace() // Thequickbrowndogjumpsoverthefoxylady.

class SpaceRemover
{
    func SpaceRemover(str :String)->String
    {
        var array = Array(str)
        var i = array.count
        while(array.last == " ")
        {
            var array1 = [Character]()
            for item in  0...i - 1
            {
                array1.append(array[item])
            }
            i = i - 1
            array = array1
            print(array1)
            print(array)

        }

        var arraySecond = array
        var j = arraySecond.count

        while(arraySecond.first == " ")
        {
            var array2 = [Character]()
            if j > 1
            {
                for item in 1..<j
                {
                    array2.append(arraySecond[item])
                }
            }
            j = j - 1
            arraySecond = array2
            print(array2)
            print(arraySecond)

        }
        print(arraySecond)
        return String(arraySecond)
    }
}

Swift 4、4.2和5

仅从前端和尾部移除空间

let str = "  Akbar Code  "
let trimmedString = str.trimmingCharacters(in: .whitespacesAndNewlines)

从字符串中的每一个地方删除空格

let stringWithSpaces = " The Akbar khan code "
let stringWithoutSpaces = stringWithSpaces.replacingOccurrences(of: " ", with: "")

羽毛球猫的答案的Swift 3版本

extension String {
    func replace(_ string:String, replacement:String) -> String {
        return self.replacingOccurrences(of: string, with: replacement, options: NSString.CompareOptions.literal, range: nil)
    }

    func removeWhitespace() -> String {
        return self.replace(" ", replacement: "")
    }
}

我会使用这个扩展，以灵活和模仿其他集合如何做到这一点:

extension String {
    func filter(pred: Character -> Bool) -> String {
        var res = String()
        for c in self.characters {
            if pred(c) {
                res.append(c)
            }
        }
        return res
    }
}

"this is a String".filter { $0 != Character(" ") } // "thisisaString"

删除开头和结尾的空格:

let trimmedString = string.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceCharacterSet())

Swift 3 / Swift 4:

let trimmedString = string.trimmingCharacters(in: .whitespaces)