The Args package includes the command name itself as the first value of the read parameter. flag.Args reads the input after the command (to be used with flag.Parse ()).

That is, os has one more command name read than flag.

package main

import (
  "flag"
  "fmt"
  "os"
)

func main() {

  // os.Args way
  args := os.Args
  if args == nil || len(args) < 2 {
    fmt.Println("Hello  The world !")
  } else {
    fmt.Println("Hello ", args[1]) //  The first 2 Number of parameters, number 1 Three arguments are the command names
  }

  // flag.Args way
  flag.Parse()
  var ch []string = flag.Args()
  if ch != nil && len(ch) > 0 {
    fmt.Println("Hello ", ch[0]) //  The first 1 Start with
  }
}

That’s all for this article, I hope you enjoy it.