Implementing traits in Rust - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to implement the trait method for the struct.

Rust

trait Greet {
    fn greet(&self) -> String;
}

struct Person {
    name: String,
}

impl Greet for Person {
    fn greet(&self) -> String {
        format!("Hello, {}!", self.[1])
    }
}

fn main() {
    let p = Person { name: String::from("Alice") };
    println!("{}", p.greet());
}

Drag options to blanks, or click blank then click option'

Agreet

Bself

CPerson

Dname

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'self' directly instead of 'self.name' inside format!.

Using the struct name 'Person' instead of the field.

The method greet uses self.name to access the name field of the Person struct.

2fill in blank

medium

Complete the code to implement the trait method that returns the area of a shape.

Rust

trait Shape {
    fn area(&self) -> f64;
}

struct Circle {
    radius: f64,
}

impl Shape for Circle {
    fn area(&self) -> f64 {
        std::f64::consts::PI * self.radius [1] self.radius
    }
}

fn main() {
    let c = Circle { radius: 3.0 };
    println!("Area: {}", c.area());
}

Drag options to blanks, or click blank then click option'

A+

B-

C*

D/

Attempts:

3 left

💡 Hint

Common Mistakes

Using + or - instead of * for multiplication.

Dividing radius by 2 instead of squaring.

The area of a circle is π times the radius squared, so we multiply radius by itself.

3fill in blank

hard

Fix the error in the trait implementation by completing the missing keyword.

Rust

trait Describe {
    fn describe(&self) -> String;
}

struct Book {
    title: String,
}

[1] Describe for Book {
    fn describe(&self) -> String {
        format!("Book: {}", self.title)
    }
}

fn main() {
    let b = Book { title: String::from("Rust Book") };
    println!("{}", b.describe());
}

Drag options to blanks, or click blank then click option'

Aimpl

Buse

Ctrait

Dstruct

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'trait' or 'struct' instead of 'impl'.

Omitting the keyword entirely.

The keyword 'impl' is used to implement a trait for a struct in Rust.

4fill in blank

hard

Fill both blanks to implement the trait method that returns a formatted string with the struct's fields.

Rust

trait Info {
    fn info(&self) -> String;
}

struct Car {
    make: String,
    year: u32,
}

impl Info for Car {
    fn info(&self) -> String {
        format!("[1] - [2]", self.make, self.year)
    }
}

fn main() {
    let car = Car { make: String::from("Toyota"), year: 2020 };
    println!("{}", car.info());
}

Drag options to blanks, or click blank then click option'

A{}

B{:?}

C{year}

D{make}

Attempts:

3 left

💡 Hint

Common Mistakes

Using named placeholders like '{year}' without matching arguments.

Using debug format '{:?}' unnecessarily.

The '{}' placeholder is used to format values in order. Both make and year are formatted with '{}'.

5fill in blank

hard

Fill all three blanks to implement a trait method that returns the full name from first and last names.

Rust

trait FullName {
    fn full_name(&self) -> String;
}

struct User {
    first_name: String,
    last_name: String,
}

impl FullName for User {
    fn full_name(&self) -> String {
        format!("[1] [2]", self.[3], self.last_name)
    }
}

fn main() {
    let user = User { first_name: String::from("John"), last_name: String::from("Doe") };
    println!("{}", user.full_name());
}

Drag options to blanks, or click blank then click option'

A{}

Bfirst_name

Clast_name

D{:?}

Attempts:

3 left

💡 Hint

Common Mistakes

Using '{:?}' instead of '{}'.

Accessing the wrong field like self.last_name twice.

The format string uses two '{}' placeholders for first and last names. The first_name field is accessed with self.first_name.