Go by Example: Switch

Switch operatorlari ko’plab tarmoqlar bo’ylab shartlarni ifodalaydi.

 
package main
 
import (
    "fmt"
    "time"
)
 
func main() {

Mana oddiy switch.

 
    i := 2
    fmt.Print("Write ", i, " as ")
    switch i {
    case 1:
        fmt.Println("one")
    case 2:
        fmt.Println("two")
    case 3:
        fmt.Println("three")
    }

Bitta case operatorida bir nechta ifodalarni ajratish uchun vergullardan foydalanishingiz mumkin. Bu misolda biz ixtiyoriy default holatidan ham foydalanamiz.

 
    switch time.Now().Weekday() {
    case time.Saturday, time.Sunday:
        fmt.Println("It's the weekend")
    default:
        fmt.Println("It's a weekday")
    }

Ifodasiz switch if/else mantiqini ifodalashning muqobil usulidir. Bu yerda biz case ifodalari konstanta bo’lmasligi mumkinligini ham ko’rsatamiz.

 
    t := time.Now()
    switch {
    case t.Hour() < 12:
        fmt.Println("It's before noon")
    default:
        fmt.Println("It's after noon")
    }

Tip switch‘i qiymatlar o’rniga tiplarni solishtiradi. Siz buni interfeys qiymatining tipini aniqlash uchun ishlatishingiz mumkin. Bu misolda t o’zgaruvchisi o’z bandiga mos keladigan tipga ega bo’ladi.

 
    whatAmI := func(i interface{}) {
        switch t := i.(type) {
        case bool:
            fmt.Println("I'm a bool")
        case int:
            fmt.Println("I'm an int")
        default:
            fmt.Printf("Don't know type %T\n", t)
        }
    }
    whatAmI(true)
    whatAmI(1)
    whatAmI("hey")
}
 
$ go run switch.go 
Write 2 as two
It's a weekday
It's after noon
I'm a bool
I'm an int
Don't know type string

Keyingi misol: .

mualliflar: Mark McGranaghan va Eli Bendersky | tarjima: @elchintoyirov | manba | litsenziya