go语言map字典删除操作的方法

package main
import "fmt"
func main(){
    var pc map[string] string
    pc = make(map[string] string)
    pc["qingdao"] = "青岛"
    pc["jinan"] = "济南"
    pc["yantai"] = "烟台"
    delete(pc,"qingdao")
    qingdao,ok := pc["qingdao"]
    if ok{
        fmt.Println(qingdao)   
    }else{
        fmt.Println("元素不存在")
    }
}