下面这段代码输出什么？

type person struct {  
    name string
}

func main() {  
    var m map[person]int
    p := person{"mike"}
    fmt.Println(m[p])
}

答 0

未初始化的map 读0值 写panic

在线运行：

读未初始化的map: https://go.dev/play/p/yVjXasOREaH

写未初始化的map: https://go.dev/play/p/2zmJGtrH-8v

写已初始化的map: https://go.dev/play/p/eUh6csag8rh