sample:
package main import ( "fmt" "math") type geometry interface { area() float64 perim() float64} type rect struct { width, height float64}type circle struct { radius float64} func (r rect) area() float64 { // rect的接口实现 return r.width * r.height}func (r rect) perim() float64 { return 2*r.width + 2*r.height} func (c circle) area() float64 { // circle的接口实现 return math.Pi * c.radius * c.radius}func (c circle) perim() float64 { return 2 * math.Pi * c.radius} func measure(g geometry) { // geometry 为上面定义的接口 fmt.Println(g) fmt.Println(g.area()) fmt.Println(g.perim())} func main() { r := rect{width: 3, height: 4} c := circle{radius: 5} measure(r) measure(c)}
$ go run interfaces.go{3 4}1214{5}78.5398163397448331.41592653589793