英文:
passing type with parameter in function call
问题
下面的代码来自Jan Newmarch关于Go网络编程的书籍。在我看到的大部分Go代码中（我是一个新手，所以看到的很少），在函数调用中不需要传递带有参数的类型。然而，在下面的代码中，你可以看到这一行：
conn.Write([]byte(daytime))
为什么在这个函数调用中需要包含[]byte？
func main() {
service := ":1200"
tcpAddr, err := net.ResolveTCPAddr("ip4", service)
checkError(err)
listener, err := net.ListenTCP("tcp", tcpAddr)
checkError(err)
for {
conn, err := listener.Accept()
if err != nil {
continue
}
daytime := time.Now().String()
conn.Write([]byte(daytime))
英文:
The code below is from Jan Newmarch's book about network programming in Go. In most of the Go code that I've seen (which is very little, as I'm a newbie, you don't (in a function call) pass a type with a parameter. However, in the code below, you see this line
conn.Write([]byte(daytime))
Why is it necessary to include []byte in this function call?
func main() {
service := ":1200"
tcpAddr, err := net.ResolveTCPAddr("ip4", service)
checkError(err)
listener, err := net.ListenTCP("tcp", tcpAddr)
checkError(err)
for {
conn, err := listener.Accept()
if err != nil {
continue
}
daytime := time.Now().String()
conn.Write([]byte(daytime))
答案1
得分: 3
Conn.Write() 期望的值是一个字节切片。由于 daytime 是字符串类型，所以你需要进行转换。
你可以将上述代码重写为：
daytime := []byte(time.Now().String())
conn.Write(daytime)
或者，如 @fabrizioM 所写，你可以使用格式化写入器进行转换：
fmt.Fprintf(conn, daytime)
英文:
Conn.Write() expects the value as a byte slice. Since daytime is of type string you have to convert it.
You could rewrite the above as:
daytime := []byte(time.Now().String())
conn.Write(daytime)
Or, as @fabrizioM writes, you could use the formatted writer which would convert it:
fmt.Fprintf(conn, daytime)
答案2
得分: 2
另一种方法是使用
fmt.Fprintf(conn, daytime)
英文:
Another way to do it is to use
fmt.Fprintf(conn, daytime)
答案3
得分: 0
因为在服务器和客户端之间传输的数据是字节(byte)。
在你的情况下，日期时间显然是字符串格式。
所以你需要使用[]byte(daytime)将其转换为字节。
另外，你可以导入"bufio"包为每个客户端创建一个NewWriter，并且NewWriter有WriteString("")方法。此时，你可以直接将你的日期时间作为参数传递进去。
英文:
Because the data being transferred between server and client is byte.
The daytime in your case is obviously string format.
So you have to convert it into byte by using []byte(daytime).
Either way, you could import "bufio" to create a NewWriter for each client, and the NewWriter
will have the methods WriteString(""). At this moment, you could directly pass your daytime
as a parameter~
通过集体智慧和协作来改善编程学习和解决问题的方式。致力于成为全球开发者共同参与的知识库，让每个人都能够通过互相帮助和分享经验来进步。
评论