A struct can have anonymous fields as well, meaning a field having no name. The type will become the field name. In below example, string will be the field name as well

type employee struct {
    string
    age    int
    salary int
}

The anonymous field can also be accessed and assigned a value

package main

import "fmt"

type employee struct {
    string
    age    int
    salary int
}

func main() {
    emp := employee{string: "Sam", age: 31, salary: 2000}
    //Accessing a struct field
    n := emp.string
    fmt.Printf("Current name is: %s\n", n)
    //Assigning a new value
    emp.string = "John"
    fmt.Printf("New name is: %s\n", emp.string)
}

Output

Current name is: Sam
New name is: John

Nested Struct

A struct can have another struct nested in it. Let’s see an example of a nested struct. In below employee struct has address struct nested it in.

package main

import "fmt"

type employee struct {
    name    string
    age     int
    salary  int
    address address
}

type address struct {
    city    string
    country string
}

func main() {
    address := address{city: "London", country: "UK"}
    emp := employee{name: "Sam", age: 31, salary: 2000, address: address}
    fmt.Printf("City: %s\n", emp.address.city)
    fmt.Printf("Country: %s\n", emp.address.country)
}

Output

City: London
Country: UK

Notice how nested struct fields are accessed.

emp.address.city
emp.address.country

Anonymous nested struct fields

The nested struct field can also be anonymous. Also, in this case, nested struct’s fields are directly accessed. So below is valid

emp.city
emp.country

It is also to be noted that below is still valid in this case

emp.address.city
emp.address.country

Let’s see a program

package main

import "fmt"

type employee struct {
	name   string
	age    int
	salary int
	address
}

type address struct {
	city    string
	country string
}

func main() {
	address := address{city: "London", country: "UK"}

	emp := employee{name: "Sam", age: 31, salary: 2000, address: address}

	fmt.Printf("City: %s\n", emp.address.city)
	fmt.Printf("Country: %s\n", emp.address.country)

	fmt.Printf("City: %s\n", emp.city)
	fmt.Printf("Country: %s\n", emp.country)
}

Output

City: London
Country: UK
City: London
Country: UK

Notice in above program that city field of address struct can be accessed in two ways

emp.city
emp.address.city

Similar for the country field of the address struct.