44_类型转换

/*

comma-ok断言:

Go语言里面有一个语法，可以直接判断是否是该类型的变量：

value, ok = element.(T)，

这里value就是变量的值，ok是一个bool类型，element是interface变量，

T是断言的类型

*/

package main

import "fmt"

type Elementer interface{}

type Person struct {

	name string

	age  int

}

func main() {

	var list []Elementer = make([]Elementer, 3) //空接口类型

	list[0] = 1

	list[1] = "ads"

	list[2] = Person{"mike", 12}

	for index, element := range list {

		if value, ok := element.(int); ok == true {

			fmt.Printf("list[%d] is an int and its value is %d
", index, value)

		} else if value, ok := element.(string); ok == true {

			fmt.Printf("list[%d] is an int and its value is %s
", index, value)

		} else if value, ok := element.(Person); ok == true {

			fmt.Printf("list[%d] is an int and its value is [%s,%d]
", index, value.name, value.age)

		}

	}

}