Defining and Using Enums

Snippet

Defining and Using Enums

Enums allow you to define a type by enumerating its possible variants. In this example, Direction has four variants representing cardinal directions. You can use match expressions to handle each variant. Enums are useful for representing a fixed set of related choices.

snippet.rs
rust
enum Direction {
    North,
    South,
    East,
    West,
}
 
fn get_opposite(dir: Direction) -> Direction {
    match dir {
        Direction::North => Direction::South,
        Direction::South => Direction::North,
        Direction::East => Direction::West,
        Direction::West => Direction::East,
    }
}
 
fn main() {
    let heading = Direction::North;
    println!("Heading: {:?}", heading);
    let opposite = get_opposite(heading);
    println!("Opposite: {:?}", opposite);
}

Breakdown

enum Direction { ... }

Defines an enum with four variants representing directions

Direction::North => Direction::South

Pattern matches each variant and returns the opposite direction

let heading = Direction::North;

Creates an instance of the enum variant

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Defining and Using Enums

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