package main
import "fmt"
// Go supports methods defined on struct types.
type rect struct {
width, height int
}
// This area method has a receiver type of *rect.
func (r *rect) area() int {
return r.width * r.height
}
// Methods can be defined for either pointer or value receiver types. Here’s
// an example of a value receiver.
func (r rect) perim() int {
return 2*r.width + 2*r.height
}
func main() {
r := rect{width: 10, height: 5}
// Here we call the 2 methods defined for our struct.
fmt.Println("area: ", r.area())
fmt.Println("perim:", r.perim())
// Go automatically handles conversion between values and pointers for
// method calls. You may want to use a pointer receiver type to avoid
// copying on method calls or to allow the method to mutate the receiving
// struct.
rp := &r
fmt.Println("area: ", rp.area())
fmt.Println("perim:", rp.perim())
}
area: 50
perim: 30
area: 50
perim: 30
Attribution
