Struct fields can be accessed through a struct pointer.
To access the field Xof a struct when we have the struct pointer p we could write (*p).X.
However, that notation is cumbersome, so the language permits us instead to write just p.X, without the explicit dereference.
func main() {
z := xy{1, 2}
p := &z
p.X = 20
fmt.Println(z)
}
package main
import "fmt"
type xy struct {
X int
Y int
}
func main() {
z := xy{1, 2}
p := &z
p.X = 20
fmt.Println(z)
}