How to give some value to []struct

[Akezhan_Esbolatov (AkezhanOb1)]

type example struct {
Example          string  `json:"example"`
Persons               []struct {
	FirstName     string `json:"firstName"`
	LastName      string `json:"lastName"`
	MiddleName    string `json:"middleName"`
	PhoneNumber   []struct {
		Carrier string `json:"carrier"`
                   Number string `json:"number"`
	} `json:"phoneNumber"`
   } `json:"persons"`
}

I have this example struct and I wanna create some instance of the struct

var ex example
ex.Example = "example"
ex.Persons[0].FirstName = "JHON"
ex.Persons[0].LastName = "DOE"
ex.Persons[0].MiddleName = "TEST"
ex.Persons[0].PhoneNumber[0].Carrier = "AT&T"
    ex.Persons[0].PhoneNumber[0].Number= "123545568"

but I get an error INDEX OUT OF BOUND, how can I assign value to the Person []Struct ?

[Yamil_Bracho]

Please check :

1. acbScoring does not exist (Maybe you mean “ex”)
2. Create a struct for PhoneNumber and another for Person

For example :

package main

type PhoneNumber struct {
	Carrier string `json:"carrier"`
	Number  string `json:"number"`
}

type Person struct {
	FirstName    string        `json:"firstName"`
	LastName     string        `json:"lastName"`
	MiddleName   string        `json:"middleName"`
	PhoneNumbers []PhoneNumber `json:"phoneNumber"`
}

type example struct {
	Example string   `json:"example"`
	Persons []Person `json:"persons"`
}

func main() {
	var ex example
	ex.Example = "example"

	ex.Persons = make([]Person, 10)
	ex.Persons[0].FirstName = "JHON"
	ex.Persons[0].LastName = "DOE"
	ex.Persons[0].MiddleName = "TEST"

	ex.Persons[0].PhoneNumbers = make([]PhoneNumber, 10)
	ex.Persons[0].PhoneNumbers[0].Carrier = "AT&T"
	ex.Persons[0].PhoneNumbers[0].Number = "123545568"
}

[NobbZ (Norbert Melzer)]

Alternatively you can also create the slice using literals:

type A struct {
  Field string
}

a := []A{
  A{ Field: "first" },
  A{ Field: "second" },
}

[Deimis (Deimantas)]

In your example you need to allocate space for Person slice because slices are not arrays. They are just like pointers, but with length and capacity parameters You better define Person as separate type, then add it to your main structure like this:

type PhoneNumber struct {
	Carrier string `json:"carrier"`
	Number  string `json:"number"`
}

type Person struct {
	FirstName    string        `json:"firstName"`
	LastName     string        `json:"lastName"`
	MiddleName   string        `json:"middleName"`
	PhoneNumbers []PhoneNumber `json:"phoneNumber"`
}

type example struct {
	Example string   `json:"example"`
	Persons []Person `json:"persons"`
}

func main() {
	ex := example{
		Example: "example",
		Persons: []Person{
			Person{
				FirstName:  "JHON",
				LastName:   "DOE",
				MiddleName: "TEST",
				PhoneNumbers: []PhoneNumber{
					PhoneNumber{
						Carrier: "AT&T",
						Number:  "123545568",
					},
				},
			},
		},
	}
	fmt.Println(ex)
}