Golang指针与interface调用实例详解

type Speaker interface {
    Speak() string
}

type Dog struct {
    Name string
}

func (d Dog) Speak() string {
    return "Woof! I'm " + d.Name
}

var s Speaker = Dog{Name: "Buddy"}
println(s.Speak()) // 输出: Woof! I'm Buddy

func (d *Dog) Bark() string {
    return "Bark! I'm " + d.Name
}

// 正确：&Dog{} 是指针，实现所有方法
var speaker Speaker = &Dog{Name: "Max"}
println(speaker.Speak()) // 可以调用，因为*Dog也有Speak方法（Go允许指针调用值方法）

type Mover interface {
    Move()
}

type Car struct{ speed int }

// 值接收者
func (c Car) Move() { println("Car moving at", c.speed) }

// 这两种赋值都合法
var m1 Mover = Car{speed: 60}
var m2 Mover = &Car{speed: 80}
m1.Move()
m2.Move()

func (c *Car) Move() { println("Car moving at", c.speed) }

var m1 Mover = Car{speed: 60} // 错误：Car没有实现Move方法
var m2 Mover = &Car{speed: 80} // 正确

type Logger interface {
    Log(msg string)
}

type ConsoleLogger struct{ prefix string }

func (cl *ConsoleLogger) Log(msg string) {
    println(cl.prefix+":", msg)
}

// 使用示例
func main() {
    var logger Logger = &ConsoleLogger{prefix: "INFO"}
    logger.Log("Program started")
}