我已经像这样初始化了两个字符常量:letemojiCharacter="?"letsimpleCharacter="a"我正在像这样打印lengthOfBytesUsingEncoding的结果:println("\(emojiCharacter)countElementsreturns\(countElements(emojiCharacter))")println("\(simpleCharacter)countElementsreturns\(countElements(simpleCharacter))")println("\(emojiCharacter)UTF16Strin