Structs

Exercises

Struct definition

// Complete the code by addressing the TODO.

struct User {
    // TODO: Something goes here
}

fn main() {
    let user = User {
        name: String::from("Tom Riddle"),
        age: 17u8,
    };
    println!("User's name: {}", user.name);
    println!("User's age: {}", user.age);
}

struct User {
  name: String,
  age: u8,
}

fn main() {
  let user = User {
      name: String::from("Tom Riddle"),
      age: 17u8,
  };
  println!("User's name: {}", user.name);
  println!("User's age: {}", user.age);
}

Mutating structs

// Make the following code compile.

struct ShopItem {
    name: String,
    quantity: u32,
    in_stock: bool,
}

fn main() {
    let item = ShopItem {
        name: String::from("Socks"),
        quantity: 200,
        in_stock: true,
    };
    // 50 pairs of socks were sold
    item.quantity -= 50;
    if item.quantity == 0 {
        item.in_stock = false;
    }
    println!("{} is in stock: {}", item.name, item.in_stock);
}

struct ShopItem {
  name: String,
  quantity: u32,
  in_stock: bool,
}

fn main() {
  let mut item = ShopItem {
      name: String::from("Socks"),
      quantity: 200,
      in_stock: true,
  };
  // 50 pairs of socks were sold
  item.quantity -= 50;
  if item.quantity == 0 {
      item.in_stock = false;
  }
  println!("{} is in stock: {}", item.name, item.in_stock);
}

Structs and Functions

// Complete the function signatures and make the code compile.

struct ShopItem {
    name: String,
    quantity: u32,
}

fn main() {
    let item = create_item("Socks", 200);
    let in_stock = is_in_stock(&item);
    println!("{} is in stock: {in_stock}", item.name);
}

fn create_item(name: &str, quantity: u32) -> {
    ShopItem {
        name: name.to_string(),
        quantity, // notice how struct initializations can be shortened when variable and field have same name
    }
}

fn is_in_stock(item) -> bool {
    item.quantity > 0
}

struct ShopItem {
  name: String,
  quantity: u32,
}

fn main() {
  let item = create_item("Socks", 200);
  let in_stock = is_in_stock(&item);
  println!("{} is in stock: {in_stock}", item.name);
}

fn create_item(name: &str, quantity: u32) -> ShopItem {
  ShopItem {
      name: name.to_string(),
      quantity,
  }
}

fn is_in_stock(item: &ShopItem) -> bool {
  item.quantity > 0
}