Match Statement

Part of the Fundamentals section of Coddy's Rust journey — lesson 26 of 75.

The match expression allows you to compare a value against a series of patterns and execute code based on which pattern matches.

Here's the basic structure of a match expression:

match variable {
	pattern1 => expression1,
	pattern2 => expression2,
	// ... more patterns
	_ => default_expression,
}

The match keyword is followed by the value you want to test.

Each arm of the match consists of a pattern followed by => and the code to execute.

The underscore _ is the default case that matches anything not matched by other patterns.

Here's an example:

let day = 3;
let day_name = match day {
	1 => "Monday",
	2 => "Tuesday",
	3 => "Wednesday",
	// ... more patterns,
	_ => "Invalid day",
};

For multiple lines of code in an arm, use a block:

let day = 3;
let day_name = match day {
	1 => {
		println!("First day of the week!");
		"Monday"
	},
	2 => "Tuesday",
	// ... other cases
	_ => "Invalid day",
};

You can match multiple patterns using |:

let day = 3;
let day_type = match day {
	1 | 2 | 3 | 4 | 5 => "Weekday",
	6 | 7 => "Weekend",
	_ => "Invalid day",
};

Match expressions in Rust must be exhaustive, meaning they must cover all possible values. The compiler will check this for you.

Challenge

Beginner

Create a program that takes a month number (1 for January, 2 for February, etc.) and prints the season it belongs to. Use a match statement for the logic.

The seasons and their corresponding months are:

Winter: December (12), January (1), February (2)
Spring: March (3), April (4), May (5)
Summer: June (6), July (7), August (8)
Autumn: September (9), October (10), November (11)

Cheat sheet

The match expression compares a value against patterns and executes code based on which pattern matches:

match variable {
    pattern1 => expression1,
    pattern2 => expression2,
    _ => default_expression,
}

Basic example:

let day = 3;
let day_name = match day {
    1 => "Monday",
    2 => "Tuesday",
    3 => "Wednesday",
    _ => "Invalid day",
};

For multiple lines of code in an arm, use a block:

let day = 3;
let day_name = match day {
    1 => {
        println!("First day of the week!");
        "Monday"
    },
    2 => "Tuesday",
    _ => "Invalid day",
};

Match multiple patterns using |:

let day = 3;
let day_type = match day {
    1 | 2 | 3 | 4 | 5 => "Weekday",
    6 | 7 => "Weekend",
    _ => "Invalid day",
};

Match expressions must be exhaustive - they must cover all possible values. The underscore _ is the default case that matches anything not matched by other patterns.

Try it yourself

use std::io;

fn main() {
    let mut input = String::new();
    io::stdin().read_line(&mut input).unwrap();
    let month: i32 = input.trim().parse().unwrap();
    // Write your code below
    let season = 

    // Don't change the line below
    println!("status = {}", season);
}