Nested Structs

A struct field may itself be another struct, allowing you to model a larger object from smaller meaningful parts.

Declare one named struct type, such as Address, then use it as a field inside Person. Read deeper fields with chained selectors like person.Home.City.

Nesting communicates ownership and structure. Because structs are values, copying a Person also copies any nested Address value fields, unless a nested field is itself a pointer or another storage-sharing type.

Follow this diagram before executing the example. Check where a value or decision changes what runs next.

This example is a complete program. Save it as main.go or paste it into the Go Playground.

Go code

package main

import "fmt"

type Address struct {
	City string
	Pin  int
}
type Person struct {
	Name string
	Home Address
}

func main() {
	person := Person{Name: "Ava", Home: Address{City: "Pune", Pin: 411001}}
	fmt.Println("Name:", person.Name)
	fmt.Println("City:", person.Home.City)
	person.Home.City = "Mumbai"
	fmt.Println("New city:", person.Home.City)
}

Output

Name: Ava
City: Pune
New city: Mumbai

The Person literal contains a complete Address struct value in the Home field. Selectors reach the city, and assigning a new city updates only that nested field.

• Nested field access uses the actual field names; names are not automatically flattened.
• Copying the outer struct also copies ordinary nested struct fields.

Add Country to Address and read it through person.Home.Country.

Tip: Edit the example above, predict the output, and run the modified code to test your reasoning.

You have practiced Nested Structs in a small, self-contained program. The important habit is to predict what runs, inspect the actual output and distinguish the language rule from the particular example.

Before continuing, make sure you can explain the program to someone who has not seen it, including the line that changes its result.