15.类的多态

package main
import "fmt"
//接口
//本质上是一个指针
type Animal interface {
    Sleep()
    GetColor() string
}
//具体的类
type Cat struct {
    color string
}
func (this *Cat) Sleep()  {
    fmt.Println("cat sleep...")
}
func (this *Cat) GetColor() string  {
    return this.color
}
func showAnimal(animal Animal)  {
    animal.Sleep()
    fmt.Println(animal.GetColor())
}
func main() {
    var animal Animal
    animal = &Cat{"black"}   //多态
    animal.Sleep()
    fmt.Println("-----------------------")
    cat:=Cat{"white"}
    showAnimal(&cat)  //对象地址传递
}