Go入门之map

map类型是引用类型，必须初始化才能使用，为key-value形式

    var userinfo = make(map[string]string)
	userinfo["username"] = "zhangsan"
	var user = map[string]string{
		"username": "张三",
		"age":      "20",
	}
	for k, v := range user {
		fmt.Printf("%v %v\n", k, v)
	}

初始化方式可以通过make方法，遍历通过range

v, ok := user["username"]
	fmt.Println(v, ok)

此为查找map中key对应的值是否存在，存在ok返回true，v返回对应的值，否决ok返回false，v返回空

删除用delete函数()

delete(user, "username")

map类型的切片

	var userinfo = make([]map[string]string, 2, 2)
	if userinfo[0] == nil {
		userinfo[0] = make(map[string]string)
		userinfo[0]["username"] = "张三"
		userinfo[0]["age"] = "20"
	}
	if userinfo[1] == nil {
		userinfo[1] = make(map[string]string)
		userinfo[1]["username"] = "张si"
		userinfo[1]["age"] = "209"
	}
	fmt.Println(userinfo)

map类型的值可以是切片

var userinfo = make(map[string][]string)
	userinfo["hobby"] = []string{
		"吃饭",
		"睡觉",
	}

	fmt.Println(userinfo)