斯威夫特3

let result = " abc ".trimmingCharacters(in: .whitespacesAndNewlines)

下面介绍如何从字符串的开头和结尾删除所有空白。

(用Swift 2.0测试的示例。)

let myString = "  \t\t  Let's trim all the whitespace  \n \t  \n  "
let trimmedString = myString.stringByTrimmingCharactersInSet(
    NSCharacterSet.whitespaceAndNewlineCharacterSet()
)
// Returns "Let's trim all the whitespace"

(用Swift 3+测试的示例。)

let myString = "  \t\t  Let's trim all the whitespace  \n \t  \n  "
let trimmedString = myString.trimmingCharacters(in: .whitespacesAndNewlines)
// Returns "Let's trim all the whitespace"

//Swift 4.0删除空格和新行

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

我创建了这个函数，允许输入字符串并返回由任意字符修剪的字符串列表

 func Trim(input:String, character:Character)-> [String]
{
    var collection:[String] = [String]()
    var index  = 0
    var copy = input
    let iterable = input
    var trim = input.startIndex.advancedBy(index)

    for i in iterable.characters

    {
        if (i == character)
        {

            trim = input.startIndex.advancedBy(index)
            // apennding to the list
            collection.append(copy.substringToIndex(trim))

            //cut the input
            index += 1
            trim = input.startIndex.advancedBy(index)
            copy = copy.substringFromIndex(trim)

            index = 0
        }
        else
        {
            index += 1
        }
    }
    collection.append(copy)
    return collection

}

As在swift中没有找到这样做的方法(在swift 2.0中编译和工作完美)

在Swift3 XCode 8 Final中

注意CharacterSet。空格不再是函数了!

(NSCharacterSet.whitespaces也不是)

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

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"