Three loose variables become one record. Add the struct at the top, then thread it through the two functions.

Add the type above main:

// Item is one record of the list — the fields that used to travel around
// as three loose variables.
type Item struct {
	Title string
	Pages int
	Read  bool
}

In main, replace the three variable lines with one literal:

	it := Item{Title: "The Go Programming Language", Pages: 380, Read: false}

Then update the two functions to take an Item and reach its fields with a dot:

func formatItem(it Item) string {
	return fmt.Sprintf("Book: %s | pages: %d | read: %v", it.Title, it.Pages, it.Read)
}

func printItem(it Item) {
	fmt.Println(formatItem(it))
}

Item{...} is a literal: it creates a record and fills the fields by name. Inside the functions, it.Title reaches a field with a dot. One value now carries what used to be three.

Verify — for the third time in a row, the same output:

App: Book list
Book: The Go Programming Language | pages: 380 | read: false

Tip. Three lessons, three refactors, zero behavior changes — the shape changes, the behavior is protected. From the next lesson the behavior finally changes too: the program becomes interactive.