Vector of structs - change value

struct Animal<'a> {
    name: &'a str,
    size: &'a str,
    weight: i32,
}

fn main() {
    let mut animals = vec![
        Animal {
            name: "elephant",
            size: "huge",
            weight: 100,
        },
        Animal {
            name: "snake",
            size: "long",
            weight: 3,
        },
    ];

    for animal in &animals {
        println!("{} - {} - {}", animal.name, animal.size, animal.weight);
    }

    animals[0].weight += 10;
    for animal in &animals {
        println!("{} - {} - {}", animal.name, animal.size, animal.weight);
    }
}

elephant - huge - 100
snake - long - 3
elephant - huge - 110
snake - long - 3