Rust Match
Pattern matching for control flow in Rust
🔍 What is Match in Rust?
Match is Rust's powerful pattern matching feature that compares values against patterns and executes code based on matches. It's like a super-powered switch statement that ensures all cases are handled.
// Basic match example
let number = 3;
match number {
1 => println!("One"),
2 => println!("Two"),
3 => println!("Three"),
_ => println!("Something else"),
}
Output:
Three
Match Patterns
Exact Values
Match specific values directly
match x {
1 => "one",
2 => "two",
_ => "other",
}Ranges
Match ranges of values
match age {
0..=12 => "child",
13..=19 => "teen",
_ => "adult",
}Enums
Match enum variants
match result {
Ok(value) => value,
Err(_) => 0,
}Guards
Add conditions to patterns
match x {
n if n > 0 => "positive",
0 => "zero",
_ => "negative",
}🔹 Basic Match Syntax
Match expressions compare a value against patterns:
fn main() {
let coin = "quarter";
let value = match coin {
"penny" => 1,
"nickel" => 5,
"dime" => 10,
"quarter" => 25,
_ => 0, // catch-all pattern
};
println!("Value: {} cents", value);
}Output:
Value: 25 cents
🔹 Matching with Option
Match is perfect for handling Option types:
fn main() {
let maybe_number = Some(42);
match maybe_number {
Some(value) => println!("Got a value: {}", value),
None => println!("No value found"),
}
// Using match in a function
let result = match maybe_number {
Some(n) => n * 2,
None => 0,
};
println!("Result: {}", result);
}Output:
Got a value: 42
Result: 84
Result: 84
🔹 Multiple Patterns
You can match multiple patterns in one arm:
fn main() {
let day = "Saturday";
let day_type = match day {
"Monday" | "Tuesday" | "Wednesday" | "Thursday" | "Friday" => "Weekday",
"Saturday" | "Sunday" => "Weekend",
_ => "Unknown",
};
println!("{} is a {}", day, day_type);
}Output:
Saturday is a Weekend