Example analysis of switch usage in Go language

This article illustrates the use of switch in the Go language. Share with you for your reference. The specific analysis is as follows:

Here you might have guessed the possible form of switch.
case will terminate automatically, unless it ends with an fallthrough statement.

package main

import (

 "fmt"

 "runtime"

)

func main() {

 fmt.Print("Go runs on ")

 switch os := runtime.GOOS; os {

 case "darwin":

  fmt.Println("OS X.")

 case "linux":

  fmt.Println("Linux.")

 default:

  // freebsd, openbsd,

  // plan9, windows...

  fmt.Printf("%s.", os)

 }

}

The execution of the switch condition from top to bottom stops when the match is successful.

(e.g.,

switch i {
case 0:
case f():
}
f is not called when i==0.)

package main

import (

 "fmt"

 "time"

)

func main() {

 fmt.Println("When's Saturday?")

 today := time.Now().Weekday()

 switch time.Saturday {

 case today+0:

  fmt.Println("Today.")

 case today+1:

  fmt.Println("Tomorrow.")

 case today+2:

  fmt.Println("In two days.")

 default:

  fmt.Println("Too far away.")

 }

}

switch without conditions is the same as switch true 1.

This 1 construct makes it possible to write long if-then-else chains in a clearer form.

package main

import (

 "fmt"

 "time"

)

func main() {

 t := time.Now()

 switch {

 case t.Hour() < 12:

     fmt.Println("Good morning!")

 case t.Hour() < 17:

     fmt.Println("Good afternoon.")

 default:

     fmt.Println("Good evening.")

 }

}

I hope this article has been helpful to the programming of Go language.