为什么我的切片在追加时没有更新?[重复]

我试图在结构中附加一个切片,但它根本不会更新。我知道go主要是通过值传递的,但片不是已经指向底层数组了吗?

我甚至尝试过通过我的change函数(使用指针?)传递这些值但我还是得到了同样的结果。

package main

import "fmt"

type BookingInfoNode struct {
    Car         string
    Date        string
    BookingTime int
}

type user struct {
    Username     string
    UserBookings []*BookingInfoNode
}

var mapUsers = make(map[string]user)

func init() {
    mapUsers["john"] = user{"john", []*BookingInfoNode{}}
}

func change(a []*BookingInfoNode, booking *BookingInfoNode) []*BookingInfoNode {
    a = append(a, booking)
    return a
}

func main() {
    newBooking := &BookingInfoNode{"mazda", "03/06/2022", 0600}
    myUser := mapUsers["john"]
    myUser.UserBookings = change(myUser.UserBookings, newBooking)

    fmt.Println(myUser.UserBookings)
    fmt.Println(mapUsers["john"].UserBookings)
}

用我的两张照片,我期待着:

[memory address]
[memory address]

但我得到了:

[memory address]
[]