Why pattern matching is needed in Rust - See It in Action

Why pattern matching is needed

📖 Scenario: Imagine you are building a simple program that checks the weather condition and suggests what to do. The weather can be sunny, rainy, or snowy. You want your program to respond differently for each case.

🎯 Goal: You will create a Rust program that uses pattern matching to handle different weather conditions and print the right suggestion. This will show why pattern matching is useful for making clear and simple decisions based on different values.

📋 What You'll Learn

Create an enum called Weather with variants Sunny, Rainy, and Snowy

Create a variable called today and set it to Weather::Rainy

Use a match expression on today with arms for each weather variant

Print a suggestion message for each weather condition inside the match arms

💡 Why This Matters

🌍 Real World

Pattern matching is used in many programs to make decisions based on different possible values, like handling user input, processing commands, or working with data that can be many types.

💼 Career

Understanding pattern matching is important for Rust developers and helps write safe, clear, and efficient code in real-world applications.

1

Create the Weather enum

Create an enum called Weather with three variants: Sunny, Rainy, and Snowy.

Rust

# Your code here

Hint

An enum groups related values under one name. Use enum Weather { Sunny, Rainy, Snowy }.

2

Create a variable for today's weather

Create a variable called today and set it to Weather::Rainy.

Rust

enum Weather {
    Sunny,
    Rainy,
    Snowy,
}

# Your code here

Hint

Use let today = Weather::Rainy; to create the variable.

3

Use match to handle weather cases

Use a match expression on today with arms for Weather::Sunny, Weather::Rainy, and Weather::Snowy. For each arm, write a comment describing what to do.

Rust

enum Weather {
    Sunny,
    Rainy,
    Snowy,
}

fn main() {
    let today = Weather::Rainy;

    match today {
        // Your code here
    }
}

Hint

Use match today { Weather::Sunny => {}, Weather::Rainy => {}, Weather::Snowy => {} }.

4

Print suggestions for each weather

Inside each match arm, use println! to print a suggestion: "It's sunny! Go outside.", "It's rainy! Take an umbrella.", and "It's snowy! Wear a coat.".

Rust

enum Weather {
    Sunny,
    Rainy,
    Snowy,
}

fn main() {
    let today = Weather::Rainy;

    match today {
        Weather::Sunny => {
            // Your code here
        }
        Weather::Rainy => {
            // Your code here
        }
        Weather::Snowy => {
            // Your code here
        }
    }
}

Hint

Use println!("message") inside each arm to show the suggestion.