Defining a Simple Closure

Part of the Logic & Flow section of Coddy's Rust journey. Lesson 60 of 66.

Now that you understand what closures are, let's learn how to define and use them in your code. The simplest way to create a closure is to assign it to a variable, which allows you to call it later.

Here's how you define a basic closure that takes no parameters:

let my_closure = || {
    println!("Hello from the closure!");
};

Notice the empty vertical bars || - this indicates that the closure takes no arguments. The curly braces contain the code that runs when you call the closure.

To call your closure, you use it just like a function by adding parentheses after the variable name:

let my_closure = || {
    println!("Hello from the closure!");
};

my_closure(); // This calls the closure and prints the message

Challenge

Easy

You will receive a single input containing a message. Create a closure that takes no parameters and prints this message. Store the closure in a variable, then call it to display the message.

Requirements:

Read the input message and trim whitespace
Create a closure using || syntax that prints the message
Store the closure in a variable
Call the closure to execute it

Input:

A single line containing a message (e.g., Welcome to Rust!)

Output:

The message printed by the closure

Try it yourself

use std::io;

fn main() {
    // Read input
    let mut message = String::new();
    io::stdin().read_line(&mut message).expect("Failed to read line");
    let message = message.trim();
    
    // TODO: Create a closure that prints the message and store it in a variable
    
    
    // TODO: Call the closure to print the message
    
}