上海知名企业面试题,看看你会吗?

Question

        public void SerializeXml(System.Xml.XmlWriter writer, object obj)
        {
            -----------这个switch语句肯定是错误的,你知道怎么改吗?
            switch (obj.GetType())
            {
                case Video:
                    SerializeXml(writer, (Video)obj);
                case Video[] :
                    SerializeXml(writer, (Video[])obj);
                case VideoResult :
                    SerializeXml(writer, (VideoResult)obj);
            }
        }        public void SerializeXml(System.Xml.XmlWriter writer, Video video)
        {
            throw new NotImplementedException();
        }        public void SerializeXml(System.Xml.XmlWriter writer, Video[] videos)
        {
            throw new NotImplementedException();
        }        public void SerializeXml(System.Xml.XmlWriter writer, VideoResult videoResult)
        {
            throw new NotImplementedException();
        }

Answer 1

switch (obj.GetType().ToString())
{
    case typeof(Video).ToString():
    .....
    case typeof(Video[]).ToString():
    ....
    case typeof(VideoResult).ToString():
    ....
}
我觉得还不如if else if好用if (obj is Video)
{
...
}
else if (obj is Video[])
{
....
}
else if (obj is VideoResult)
{
.....
}

Answer 2

如果只有3个用 if还好些    我看也是break