Day13:Sort Vector - 100DayOfRust

Sort vector: use sort and sort_by method

#[derive(Debug, Eq, Ord, PartialEq, PartialOrd)]
struct Person {
    name: &'static str,
    age: i32,
}


fn main() {
    // sort vector of int
    let mut v = vec![3, 1, 4, 2, 5];
    v.sort();
    println!("V is {:?}", v);

    // sort vector of float
    // float number implemented PartialOrder trait
    let mut v2 = vec![1.3, 3.2, 1.05, 2.3];
    v2.sort_by(|a, b| a.partial_cmp(b).unwrap());
    println!("V2 is {:?}", v2);

    // sort vector of self-defined struct
    let mut v3 = vec![
        Person {name: "Bob", age: 12},
        Person {name: "Alice", age: 18},
        Person {name: "Chris", age: 17}
    ];
    v3.sort_by(|a, b| a.age.cmp(&b.age));
    println!("V3 is {:?}", v3);

    v3.sort_by(|a, b| a.name.cmp(&b.name));
    println!("V3 is {:?}", v3);

    // we can directly call sort b/c struct
    // has derived Eq, Order, PartialEq and PartialOrder
    v3.sort();
    println!("V3 is {:?}", v3);

}

Result:

V is [1, 2, 3, 4, 5]
V2 is [1.05, 1.3, 2.3, 3.2]
V3 is [Person { name: "Bob", age: 12 }, Person { name: "Chris", age: 17 }, Person { name: "Alice", age: 18 }]
V3 is [Person { name: "Alice", age: 18 }, Person { name: "Bob", age: 12 }, Person { name: "Chris", age: 17 }]
V3 is [Person { name: "Alice", age: 18 }, Person { name: "Bob", age: 12 }, Person { name: "Chris", age: 17 }]