Go之断言

说明断言使用的例子

type Element interface{}
type List [] Element

type Person struct {
    name string
    age int
}

//打印
func (p Person) String() string {
    return "(name: " + p.name + " - age: "+strconv.Itoa(p.age)+ " years)"
}

func main() {
    list := make(List, 3)
    list[0] = 1 //an int
    list[1] = "Hello" //a string
    list[2] = Person{"Dennis", 70}

    for index, element := range list{
        switch value := element.(type) {
        case int:
            fmt.Printf("list[%d] is an int and its value is %d\n", index, value)
        case string:
            fmt.Printf("list[%d] is a string and its value is %s\n", index, value)
        case Person:
            fmt.Printf("list[%d] is a Person and its value is %s\n", index, value)
        default:
            fmt.Println("list[%d] is of a different type", index)
        }
    }
}