查看NSCharacterSet(Swift)中的字符

Question

当我试图在这样的NSCharacterSet中列出字符时

print(NSCharacterSet.URLQueryAllowedCharacterSet())

它不打印字符,而是类似的东西

<__ NSCFCharacterSet:0x1759b900>

Answer 1

基于另一个答案,这里是Swift 2.0/3.0中的派生清洁版:

extension NSCharacterSet {
    var characters:[String] {
        var chars = [String]()
        for plane:UInt8 in 0...16 {
            if self.hasMemberInPlane(plane) {
            let p0 = UInt32(plane) << 16
            let p1 = (UInt32(plane) + 1) << 16
            for c:UTF32Char in p0..<p1 {
                    if self.longCharacterIsMember(c) {
                        var c1 = c.littleEndian
                        let s = NSString(bytes: &c1, length: 4, encoding: NSUTF32LittleEndianStringEncoding)!
                        chars.append(String(s))
                    }
                }
            }
        }
        return chars
    }
}

用法:

let charset = NSCharacterSet.URLQueryAllowedCharacterSet()
print(charset.characters.joinWithSeparator(""))