How to initalize a nested list in Golang? [duplicate] - go

Question

This question already has answers here:
How to initialize nested struct in golang?
(2 answers)
initializing a struct containing a slice of structs in golang
(2 answers)
Closed 10 months ago.
I have a nested struct like this:
type Project struct {
FolderStructure []FolderItem
Description string
}
type FolderItem struct {
SubFolderStructure []SubFolderItem
Description string
}
type SubFolderItem struct {
SubSubFolderStructure []SubSubFolderItem
Description string
}
type SubSubFolderItem struct {
Content string
Description string
}
I wonder how to initalize it, otherwise invalid memory address or nil pointer dereference will be thrown out.
Thanks in advance!

Answer 1

The easiest way to initialize is to create multiple instances as variables & then reuse them to assign the values to the nested structures.
Here is the working example: https://go.dev/play/p/6p3VFljyqom and same below, this is just one way of doing it and feel it's the easiest.
package main
import "fmt"
type Project struct {
FolderStructure []FolderItem
Description string
}
type FolderItem struct {
SubFolderStructure []SubFolderItem
Description string
}
type SubFolderItem struct {
SubSubFolderStructure []SubSubFolderItem
Description string
}
type SubSubFolderItem struct {
Content string
Description string
}
func main() {
ssfi1 := SubSubFolderItem{
"content1",
"description1 - SubSubFolderItem",
}
ssfi2 := SubSubFolderItem{
"content2",
"description2 - SubSubFolderItem",
}
sfi := SubFolderItem{
SubSubFolderStructure: []SubSubFolderItem{ssfi1, ssfi2},
Description: "description 1 - SubFolderItem",
}
fi := FolderItem{
SubFolderStructure: []SubFolderItem{sfi, sfi},
Description: "description 1 - FolderItem",
}
p := Project{
FolderStructure: []FolderItem{fi, fi},
Description: "description 1 - Project",
}
fmt.Println(ssfi1)
fmt.Println(ssfi2)
fmt.Println(sfi)
fmt.Println(fi)
fmt.Println(p)
}