Go from introduction to practice - Interface (notes)

Java Interface

Go Interface

type Mover interface {
    
	move()
}

type dog struct {
    }

func (d dog) move() {
    
	fmt.Println(" The dog can move ")
}

func main() {
    
	var x Mover
	var wangcai = dog{
    } //  Wangcai is dog type 
	x = wangcai         // x You can receive dog type 
	var fugui = &dog{
    }  //  Wealth is *dog type 
	x = fugui           // x You can receive *dog type 
	x.move()
}

From the above code, we can find , After implementing the interface with the value receiver , Whether it's dog Structure or structure pointer *dog All variables of type can be assigned to the interface variable . because Go There is a syntax sugar for evaluating pointer type variables ,dog The pointer fugui The interior will automatically evaluate *fugui

func (d *dog) move() {
    
	fmt.Println(" The dog can move ")
}
func main() {
    
	var x Mover
	var wangcai = dog{
    } //  Wangcai is dog type 
	x = wangcai         // x Can't accept dog type 
	var fugui = &dog{
    }  //  Wealth is *dog type 
	x = fugui           // x You can receive *dog type 
}

At this time Mover The interface is *dog type , So we can't give x Pass in dog Type of wangcai, here x Can only store *dog Type value .

Interface variables

Custom type