A structure or struct in Golang is a user-defined type, which allows us to create a group of elements of different types into a single unit. Any real-world entity which has some set of properties or fields can be represented as a struct. Go language allows nested structure. A structure which is the field of another structure is known as Nested Structure. Or in other words, a structure within another structure is known as a Nested Structure. Syntax:
type struct_name_1 struct{
// Fields
}
type struct_name_2 struct{
variable_name struct_name_1
}
Let us discuss this concept with the help of the examples:
Example 1:
C
// Golang program to illustrate// the nested structurepackage mainimport "fmt"// Creating structuretype Author struct { name string branch string year int}// Creating nested structuretype HR struct { // structure as a field details Author}func main() { // Initializing the fields // of the structure result := HR{ details: Author{"Sona", "ECE", 2013}, } // Display the values fmt.Println("\nDetails of Author") fmt.Println(result)} |
Output:
Details of Author
{{Sona ECE 2013}}
Example 2:
C
// Golang program to illustrate// the nested structurepackage mainimport "fmt"// Creating structuretype Student struct { name string branch string year int}// Creating nested structuretype Teacher struct { name string subject string exp int details Student}func main() { // Initializing the fields // of the structure result := Teacher{ name: "Suman", subject: "Java", exp: 5, details: Student{"Bongo", "CSE", 2}, } // Display the values fmt.Println("Details of the Teacher") fmt.Println("Teacher's name: ", result.name) fmt.Println("Subject: ", result.subject) fmt.Println("Experience: ", result.exp) fmt.Println("\nDetails of Student") fmt.Println("Student's name: ", result.details.name) fmt.Println("Student's branch name: ", result.details.branch) fmt.Println("Year: ", result.details.year)} |
Output:
Details of the Teacher Teacher's name: Suman Subject: Java Experience: 5 Details of Student Student's name: Bongo Student's branch name: CSE Year: 2
Example 3:
In Go, a structure can have fields that are themselves structures, which are called nested structures. Here is an example of a struct that has a nested struct:
Go
package mainimport ( "fmt")type Address struct { Street string City string State string PostalCode string}type Person struct { FirstName string LastName string Age int Address Address}func main() { p := Person{ FirstName: "John", LastName: "Doe", Age: 30, Address: Address{ Street: "123 Main St", City: "Anytown", State: "CA", PostalCode: "12345", }, } fmt.Println(p.FirstName, p.LastName) fmt.Println("Age:", p.Age) fmt.Println("Address:") fmt.Println("Street:", p.Address.Street) fmt.Println("City:", p.Address.City) fmt.Println("State:", p.Address.State) fmt.Println("Postal Code:", p.Address.PostalCode)} |
Output:
John Doe
Age: 30
Address:
Street: 123 Main St
City: Anytown
State: CA
Postal Code: 12345
Here, we define two struct types: Person and Address. Person has a nested struct field Address. In the main function, we create a new Person instance with an Address field. Then, we print out the values of various fields of the Person and Address structs using dot notation to access the nested fields.
