Nested Struct in Go

A Struct which has a field of another struct is called Nested struct

Example :

 package main
 import "fmt"
 type User struct {
	name    string
	age     int
	address Address
 }
 type Address struct {
	city    string
	state   string
	pincode int
 }
 func main() {
 	// declare a struct variable & initialize it after
	var user1 User
	user1.name = "vicky"
	user1.age = 22
	user1.address.city = "chennai"
	user1.address.state = "tamilnadu"
	user1.address.pincode = 600001

	// declaration and initialization of nested struct 
	user2 := User{"tejas", 23, Address{"madurai", "tamilnadu", 600001}}

	fmt.Println(user1)
	fmt.Println(user2)
 }

Output:

user 1 :  {vicky 22 {chennai tamilnadu 600001}}
user 2 :  {tejas 23 {madurai tamilnadu 600001}}

Important Note: we can embed an another struct into a struct by anonymously providing no name to the struct field

 package main
 import "fmt"
 type User struct {
	name string
	age  int
	// here we are providing a name to nested struct field [anonymous filed]
	// basically we are embedding the another struct[Address] fields to this struct[User] 
	Address
 }
 type Address struct {
	city    string
	state   string
	pincode int
 }
 func main() {

	user := User{"tejas", 23, Address{"madurai", "tamilnadu", 600001}}

	fmt.Println("Name :", user.name)
	fmt.Println("Age :", user.age)
	
	// user variable can directly access the address struct fields
	fmt.Println("City :", user.city)
	fmt.Println("State :", user.state)
	fmt.Println("Pincode :", user.pincode)
 }

Output:

Name : tejas
Age : 23
City : madurai
State : tamilnadu
Pincode : 600001