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# Nested Structure in Golang

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 structure``package main` `import "fmt"` `// Creating structure``type Author ``struct` `{``    ``name   string``    ``branch string``    ``year   ``int``}` `// Creating nested structure``type 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 structure``package main` `import "fmt"` `// Creating structure``type Student ``struct` `{``    ``name   string``    ``branch string``    ``year   ``int``}` `// Creating nested structure``type 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` `main` `import` `(``    ``"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.

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