Value receivers in Go - Mini Project: Build & Apply

Understanding Value Receivers in Go

📖 Scenario: Imagine you are creating a simple program to manage a book's information. You want to understand how changing a book's title inside a method affects the original book data.

🎯 Goal: You will create a Book struct and a method with a value receiver that tries to change the book's title. You will see if the original book's title changes or not.

📋 What You'll Learn

Create a Book struct with a title field of type string

Create a method ChangeTitle with a value receiver that changes the title field

Create a Book variable with an initial title

Call the ChangeTitle method on the Book variable

Print the book's title before and after calling ChangeTitle

💡 Why This Matters

🌍 Real World

Value receivers are used in Go when you want methods to work on copies of data, ensuring the original data stays unchanged. This is useful in many programs where data safety is important.

💼 Career

Understanding value vs pointer receivers is essential for Go developers to write efficient and bug-free code, especially when working with structs and methods.

1

Create the Book struct

Create a struct called Book with one field title of type string.

Go

// Your code here

Hint

Use the type keyword to define a struct named Book with a title field.

2

Create the ChangeTitle method with a value receiver

Create a method called ChangeTitle with a value receiver of type Book. Inside the method, set the title field to "New Title".

Go

package main

type Book struct {
    title string
}

// Your code here

Hint

Define a method with func (b Book) ChangeTitle() and change b.title inside it.

3

Create a Book variable and call ChangeTitle

Create a variable called myBook of type Book with the title "Original Title". Then call myBook.ChangeTitle().

Go

package main

type Book struct {
    title string
}

func (b Book) ChangeTitle() {
    b.title = "New Title"
}

// Your code here

Hint

Create myBook with Book{title: "Original Title"} and call myBook.ChangeTitle().

4

Print the book title before and after calling ChangeTitle

Add fmt.Println statements to print myBook.title before and after calling myBook.ChangeTitle(). Import fmt package as needed.

Go

package main

import "fmt"

type Book struct {
    title string
}

func (b Book) ChangeTitle() {
    b.title = "New Title"
}

func main() {
    myBook := Book{title: "Original Title"}
    // Print title before change
    // Call ChangeTitle
    // Print title after change
    // Your code here
}

Hint

Use fmt.Println(myBook.title) before and after calling ChangeTitle() to see if the title changes.