Question

我不确定swift 2中的API是否已更改，但我无法使用过滤器来处理Swift 2中的字符串。以下内容应将“abc123 $$$ ff”更改为“abcff”。

// Removes all special characters and whitespaces
func compressString(aString: String) -> String{
    let charSet = NSCharacterSet.letterCharacterSet()

// The following don't work:
//    return aString.filter{charSet.contains($0)}
//    return String(filter(aString).{charSet.contains($0)})
}

Answer 1

int val = (int)Char.GetNumericValue(Console.Read())

您还可以创建扩展程序以简化代码：

func compressString(aString: String) -> String {
    let letterSet = NSCharacterSet.letterCharacterSet()
    return String(aString.characters.filter{letterSet.characterIsMember(String($0).utf16.first!)})
}

let str = "abc123$$$ ff"
compressString(str)   // abcff

Answer 2

如果要使用过滤器，则需要在字符视图上运行它：

// Removes all special characters and whitespaces
func compressString(aString: String) -> String{
    let charSet: [Character] = ["$", " ", "1", "2", "3"]

    // The following don't work:
    return String(aString.characters.filter { !charSet.contains($0) })
}

let before = "abc123$$$ ff"


let after = compressString(before) // "abcff"

在Swift 2中的字符串上使用filter（）

2 个答案: