44_类型转换

Posted 2022-11-21 zhaopp

/*

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\n", index, value)

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

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

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

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