2、go Defer

package main

import (
   "fmt"
   "os"
)

func main()  {
   f:=createFile("D:\\webfront\\defer.txt")
   defer closeFile(f)
   writeFile(f)
}

func createFile(p string) *os.File{
   fmt.Println("creating")

   f,err :=os.Create(p)

   if err!=nil {
      panic(err)
   }

   return  f

}

func writeFile(f *os.File){
   fmt.Println("writing")
   fmt.Fprintln(f,"data")
}

func closeFile(f *os.File){
   fmt.Println("closing")
   f.Close()
}