Why methods are used in Go - See It in Action

Why methods are used

📖 Scenario: Imagine you have a simple program that keeps track of a book's details. You want to organize the code so that actions related to the book, like showing its title or updating its page count, are grouped together. This makes the program easier to understand and use.

🎯 Goal: You will create a Go program that defines a Book type and uses methods to show the book's title and update its page count. This will help you see why methods are useful to group actions with the data they belong to.

📋 What You'll Learn

Create a struct called Book with fields title (string) and pages (int).

Create a method called ShowTitle for Book that prints the book's title.

Create a method called UpdatePages for Book that changes the page count.

Create a main function to create a Book instance, call ShowTitle, update pages, and then print the new page count.

💡 Why This Matters

🌍 Real World

In real programs, methods help keep data and the actions on that data together, like a book knowing how to show its title or update its pages.

💼 Career

Understanding methods is key for writing clean, organized code in Go, which is important for many software development jobs.

1

Create the Book struct

Create a struct called Book with two fields: title of type string and pages of type int.

Go

// Define the Book struct with title and pages fields
// Your code here

Hint

Use the type keyword to define a struct. Inside curly braces, list the fields with their types.

2

Add the ShowTitle method

Add a method called ShowTitle with a receiver of type *Book that prints the book's title using fmt.Println. Import fmt package if needed.

Go

package main

import "fmt"

// Add ShowTitle method for *Book receiver
// Your code here

Hint

Define a method with func (b *Book) ShowTitle(). Use fmt.Println to print b.title.

3

Add the UpdatePages method

Add a method called UpdatePages with a receiver of type *Book that takes an int parameter called newPages and updates the pages field of the book.

Go

package main

import "fmt"

// Add UpdatePages method for *Book receiver
// Your code here

Hint

Define a method with func (b *Book) UpdatePages(newPages int). Inside, set b.pages = newPages.

4

Use the methods in main

In the main function, create a Book variable called myBook with title "Go Basics" and pages 100. Call myBook.ShowTitle(), then call myBook.UpdatePages(150), and finally print the updated pages using fmt.Println(myBook.pages).

Go

package main

import "fmt"

func main() {
    // Create myBook variable
    // Call ShowTitle method
    // Call UpdatePages method with 150
    // Print updated pages
    // Your code here
}

Hint

Use myBook := Book{title: "Go Basics", pages: 100} to create the book. Call methods with myBook.ShowTitle() and myBook.UpdatePages(150). Print pages with fmt.Println(myBook.pages).