Defining modules in Rust - Mini Project: Build & Apply

Defining modules

📖 Scenario: You are organizing a small Rust program that manages book information. To keep your code clean and easy to understand, you want to split it into modules.

🎯 Goal: You will create a module named library that contains a function to display a book's title. Then you will call this function from the main program.

📋 What You'll Learn

Create a module named library

Inside library, define a public function print_book_title that prints the book title

Call library::print_book_title from the main function

💡 Why This Matters

🌍 Real World

Modules help organize large programs by grouping related code together, making it easier to maintain and understand.

💼 Career

Understanding modules is essential for writing clean, scalable Rust code in professional software development.

1

Create the library module

Create a module named library using mod library { } syntax.

Rust

# Your code here

Hint

Use mod library { } to define the module.

2

Add a public function print_book_title inside library

Inside the library module, define a public function named print_book_title that prints "Book title: The Rust Book".

Rust

mod library {
    // Your code here
}

fn main() {
}

Hint

Use pub fn print_book_title() { println!("Book title: The Rust Book"); } inside the module.

3

Call print_book_title from main

In the main function, call the function print_book_title from the library module using library::print_book_title().

Rust

mod library {
    pub fn print_book_title() {
        println!("Book title: The Rust Book");
    }
}

fn main() {
    // Your code here
}

Hint

Call the function with library::print_book_title(); inside main.

4

Print the output

Run the program and print the output from calling library::print_book_title().

Rust

mod library {
    pub fn print_book_title() {
        println!("Book title: The Rust Book");
    }
}

fn main() {
    library::print_book_title();
    // Your code here
}

Hint

The program should print exactly Book title: The Rust Book.