go-by-example/methods/methods.go
2023-12-18 03:40:05 -05:00

34 lines
No EOL
811 B
Go

package main
import "fmt"
type rect struct {
width, height int
}
//this area method has a reciever type of *rect
func (r *rect) area() int {
return r.width * r.height
}
// Methods can be defined for either pointer or value reciever types
// heres 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 two 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())
}