--- id: 26048172-107d-4ad4-9906-acdf7935dfcb title: Rust Structs Syntax --- # Basics ``` rust struct User { username: String, email: String, sign_in_count: u64, active: bool, } fn build_user(email: String, username: String) -> User { // When struct field name and parameter name are the same shorthand syntax can be used User { email, username, active: true, sign_in_count: 1, } } fn print_data(user: User) { println!("User email is: {}", user.email); println!("User username is: {}", user.username); println!("User sign in count is: {}", user.sign_in_count); println!("User active is: {}", user.active); } fn main() { let user1 = build_user( String::from("someone@example.com"), String::from("someusername123"), ); println!("User 1"); print_data(user1); let mut user2 = User { email: String::from("someone@example.com"), username: String::from("someusername123"), active: true, sign_in_count: 1, }; user2.email = String::from("anotheremail@example.com"); println!("User 2"); print_data(user2); } ``` ``` rust ``` # Tuple Struct ``` rust fn main() { struct Color(i32, i32, i32); struct Point(i32, i32, i32); let black = Color(0, 0, 0); let origin = Point(0, 0, 0); } ``` # Debug trait To print out debugging information we have the [debug trait](https://doc.rust-lang.org/std/fmt/trait.Debug.html): ``` rust #[derive(Debug)] struct Rectangle { width: u32, height: u32, } fn main() { let rect1 = Rectangle { width: 30, height: 50, }; println!("rect1 is {:?}", rect1); } ``` # Methods Methods are like functions, but for structs: ``` rust #[derive(Debug)] struct Rectangle { width: u32, height: u32, } impl Rectangle { fn area(&self) -> u32 { self.width * self.height } } fn main() { let rect1 = Rectangle { width: 30, height: 50, }; println!( "The area of the rectangle is {} square pixels.", rect1.area() ); } ``` # Associated Functions These are Rust's take on static functions. They **don't** take `self` as a parameter ``` rust #[derive(Debug)] struct Rectangle { width: u32, height: u32, } impl Rectangle { fn area(&self) -> u32 { self.width * self.height } fn square(size: u32) -> Rectangle { Rectangle { width: size, height: size, } } } fn main() { let rect1 = Rectangle::square(10); println!( "The area of the rectangle is {} square pixels.", rect1.area() ); } ```