rustlings/exercises/03_if/if3.rs

fn animal_habitat(animal: &str) -> &str {
    // TODO: Fix the compiler error in the statement below.
    //
    // Hint: every `if` / `else if` / `else` branch must produce the same type.
    // A floating-point literal, a string, and integers cannot be mixed in one chain.
    // For unknown animals, use another integer identifier (for example `4`) instead of
    // a string, then keep the habitat checks below unchanged.
    let identifier = if animal == "crab" {
        1
    } else if animal == "gopher" {
        2.0
    } else if animal == "snake" {
        3
    } else {
        "Unknown"
    };

    // Don't change the expression below!
    if identifier == 1 {
        "Beach"
    } else if identifier == 2 {
        "Burrow"
    } else if identifier == 3 {
        "Desert"
    } else {
        "Unknown"
    }
}

fn main() {
    // You can optionally experiment here.
}

// Don't change the tests!
#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn gopher_lives_in_burrow() {
        assert_eq!(animal_habitat("gopher"), "Burrow")
    }

    #[test]
    fn snake_lives_in_desert() {
        assert_eq!(animal_habitat("snake"), "Desert")
    }

    #[test]
    fn crab_lives_on_beach() {
        assert_eq!(animal_habitat("crab"), "Beach")
    }

    #[test]
    fn unknown_animal() {
        assert_eq!(animal_habitat("dinosaur"), "Unknown")
    }
}