Why is thie map creating a new copy?

[Subramanian_Swaminat (Subramanian Swaminathan)]

why are Tel.lookup[“idx”].value and Tel.m.value not the same values… i thought i was saving the reference in the map and when i put the reference out and update it i get a copy of the variable ?

playground link
https://goplay.space/#8HAHI9WG12-

package main

import (
“fmt”
)

func main() {
var Tel PkgVar = *Init()
Tel.lookup[“idx”].value = “NewValue”
fmt.Println(Tel.lookup[“idx”].value) <— why are these not the same?
fmt.Println(Tel.m.value) <–
}

func Init() *PkgVar {
var p PkgVar
p.m = metric{“Original_value”}
p.lookup = map[string]*metric{
“idx”: &p.m,
}
return &p
}

type PkgVar struct {
m metric
lookup map[string]*metric
}

type metric struct {
value string
}

[j-forster (Johann Forster)]

Please format your code using three backticks like this: ``` your code here ```.
This makes it much easier to read your code in this forum.

---

By doing this assignment var Tel PkgVar = *Init() you dereference the value and create a copy of that value.
Now Tel.lookup["idx"] still points to &p.m from the Init() function, which is not to same as Tel.m (the local variable).

You can change the assignment to var Tel *PkgVar = Init() so solve that problem.