Rust 1.87.0
17067e9ac

Match

There is a new edition of the book and this is an old link.

match allows us to compare a value against a series of patterns and then execute code based on which pattern matches. Patterns can be made up of literal values, variable names, wildcards, and many other things.

enum Coin {
    Penny,
    Nickel,
    Dime,
    Quarter,
}

fn value_in_cents(coin: Coin) -> u32 {
    match coin {
        Coin::Penny => 1,
        Coin::Nickel => 5,
        Coin::Dime => 10,
        Coin::Quarter => 25,
    }
}

Here are the relevant sections in the new and old books:

• in the current edition: Ch 6.02 — The match Control Flow Operator
• in the current edition: Ch 19.00 — Patterns
• In the first edition: Ch 3.14 — Match