golang 往页面写入内容方法

import (
    "fmt"
    "html/template"
    "io"
    "log"
    "net/http"
)
func writeHandler(w http.ResponseWriter, r *http.Request) {
    w.Write([]byte("hello"))
    io.WriteString(w, "hello io.writestring")
    fmt.Fprintf(w, "abc")
    return
}