interface_t1.go

package main

import (
    "fmt"
    "strconv"
)

type Element interface{}
type List []Element

type Person struct {
    name string
    age  int
}

// 实现了fmt.Stringer接口
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) { // switch类型判断开关
        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)
        }
    }
}