package main

import (

    "fmt"

    "io/ioutil"

    "os"

)

func main() {

    filename := "a.txt"

    //--------- create file ----------

    file, err := os.Create(filename)

    if err != nil {

        fmt.Println(err)

    }

    defer file.Close()

    str := "你好,世界"

    data := []byte(str)

    err = ioutil.WriteFile(filename, data, )

    //--------- read file ------------

    buf := make([]byte, )

    n, err := file.Read(buf)

    if err != nil {

        fmt.Println(err)

    }

    fmt.Printf("------------method 1-------------\n%v\n", buf)

    fmt.Printf("--> 读取长度:%v\n", n)

    fmt.Printf("--> %v,\n", string(buf))

    //------------ read file method 2 ---------

    res, err := ioutil.ReadFile(filename)

    if err != nil {

        fmt.Println(err)

    }

    fmt.Println("---------- method 2----------")

    fmt.Println(string(res))

}

$ go run main.go

------------method -------------

[                   ]

--> 读取长度:

--> 你好,世界,

---------- method ----------

你好,世界