go语言自定义结构体实现io.Write接口

 go语言自定义结构体实现io.Write接口，并测试func Fprintf(w io.Writer, format string, a ...interface{}) (n int, err error) 函数。

package main

import "fmt"

type Demo struct {
    ByteBuffer []byte
}

func (demo *Demo)Write(p []byte) (n int, err error)  {
    for _,v:=range p {
        demo.ByteBuffer = append(demo.ByteBuffer, v)
    }
    return len(p),nil
}


func main() {
    var demo Demo
    fmt.Printf("%s\n",string(demo.ByteBuffer))
    fmt.Fprintf(&demo,"Hello, %s","世界!")
    fmt.Printf("%s\n",string(demo.ByteBuffer))
}

输出：