方法是先用这几个codeUnit做成NSData,然后再转成NSString,就能得到对应的字符串了。

 import Foundation
var bytes:[Byte]=[240,159, 144, 182]
let data = NSData(bytes: bytes, length: bytes.count)
let dogString:String = NSString(data: data, encoding: NSUTF8StringEncoding)

顺便一提，1F436这个16进制数，也能直接通过UnicodeScalar转换成字符串，就像下面这样

 var dogInt:UInt32=0x1F436
let dog:String=UnicodeScalar(dogInt).escape(asASCII: false)

DOG FACE