Go by Example: Interfaces

Interfeyslar - bu metod imzolarining nomlangan to’plamlaridir.

 
package main
 
import (
    "fmt"
    "math"
)

Mana geometrik shakllar uchun asosiy interfeys.

 
type geometry interface {
    area() float64
    perim() float64
}

Misolimiz uchun biz ushbu interfeysni rect va circle tiplarida amalga oshiramiz.

 
type rect struct {
    width, height float64
}
type circle struct {
    radius float64
}

Go’da interfeysni amalga oshirish uchun biz shunchaki interfeysdagi barcha metodlarni amalga oshirishimiz kerak. Bu yerda biz rect larda geometry ni amalga oshiramiz.

 
func (r rect) area() float64 {
    return r.width * r.height
}
func (r rect) perim() float64 {
    return 2*r.width + 2*r.height
}

circle lar uchun amalga oshirish.

 
func (c circle) area() float64 {
    return math.Pi * c.radius * c.radius
}
func (c circle) perim() float64 {
    return 2 * math.Pi * c.radius
}

Agar o’zgaruvchi interfeys tipiga ega bo’lsa, biz nomlangan interfeysdagi metodlarni chaqira olamiz. Mana istalgan geometry ustida ishlash uchun bundan foydalanadigan generik measure funksiyasi.

 
func measure(g geometry) {
    fmt.Println(g)
    fmt.Println(g.area())
    fmt.Println(g.perim())
}

Ba’zan interfeys qiymatining runtime tipini bilish foydali bo’ladi. Bir variant - bu yerda ko’rsatilganidek tip tasdig’i dan foydalanish; boshqasi esa tip switch.

 
func detectCircle(g geometry) {
    if c, ok := g.(circle); ok {
        fmt.Println("circle with radius", c.radius)
    }
}
 
func main() {
    r := rect{width: 3, height: 4}
    c := circle{radius: 5}

circle va rect struct tiplari ikkalasi ham geometry interfeysini amalga oshiradi, shuning uchun biz ushbu structlarning namunalarini measure ga argument sifatida ishlatishimiz mumkin.

 
    measure(r)
    measure(c)
 
    detectCircle(r)
    detectCircle(c)
}
 
$ go run interfaces.go
{3 4}
12
14
{5}
78.53981633974483
31.41592653589793
circle with radius 5

Go interfeyslari ichkarida qanday ishlashini tushunish uchun ushbu blog postini ko’rib chiqing.

Keyingi misol: .

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