interface

《How to use interfaces in Go》

行为定义 / Behavior Definition

type Speaker interface {
    Speak() string
}

类型判断 / Type Assertion & Type Switch

var s Speaker = Person{Name: "Bob"}

if p, ok := s.(Person); ok {
    fmt.Println("It's a Person:", p.Name)
}

switch v := s.(type) {
case Person:
    fmt.Println("Person:", v.Name)
default:
    fmt.Println("Unknown type")
}