Difference between revisions of "Rust-Programming-Language/C2/Tuples-and-Struct/English"

Title Slide

Learning Objectives

• Tuples and
• Struct

System Requirements

• Ubuntu Linux OS version 22.04
• Rust version 1.80.0
• Visual Studio Code version 1.19.0

Prerequisites

Code Files

• The following code file is required to practise this tutorial.
• This file is provided in the Code Files link of this tutorial page.

Tuples

• Tuple is a compound data type
• It is a group of values of different types, stored in a single variable.
• Tuples have a fixed length - once declared they cannot grow or shrink in size.

> cargo new tuplesdemo

In the menu bar, File >> Open folder

>> Desktop >> MyRustProject >> tuplesdemo

Type the command cargo new tuplesdemo and press Enter.

Open the created project as shown.

let person: (f64, u8, bool) = (18000.00, 30, true);

println!("salary: {}", person.0);

println!("Age: {}", person.1);

println!("Is Active: {}", person.2);

// Destructuring a tuple

let(salary,age,status) =person;

println!("Destructured - Salary: {}, Age: {}, Status: {}", salary, age, status);

}

Press Ctrl+S

Here the tuple is declared with floating-point, integer and boolean data type.

We can access tuple elements using dot notation followed by the index of the element.

0 for the first element, 1 for the second, and so on.

Destructuring means it breaks the tuple into individual variables.

Here, salary becomes "18000", age becomes 30, and status becomes “true”.

It prints values stored in the new variables.

Save the program.

In the terminal, type cargo run.

Point to the output.

fn get_coordinates() -> (i32, i32) {

(10, 20)

}

fn main() {

let (x, y) = get_coordinates();

println!("X: {}, Y: {}", x, y);

}

This code shows that Tuples are commonly used to return multiple values from a function.

Save the file.

Struct

• Structs are similar to tuples
• Structs can also hold multiple related values, of different data types.

Clear the window and copy and paste the code from the code file.

    active: bool,

    username: String,

    email: String,

}

fn main() {

    let user1 = User {

        active: true,

        username: String::from("someusername123"),

        email: String::from("someone@example.com"),

    };

println!(“{:?}”,user1.email);

}

Press Ctrl+S

We define a struct named User.

The fields with their names and data types are specified within the curly braces.

It groups together multiple pieces of data related to a user account.

user1 is a variable of type User.

User creates an instance of the User struct and assigns it to user1 variable.

We have the flexibility to assign key value pairs in any order, as struct is just a template.

To get a specific value from a struct, we use dot notation.

For example, to access this user’s email address, we use user1.email

Save the program.

Copy and paste the code from the code file.

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 {}",

rect1.area()

);

}

Press Ctrl+ S

We use an impl( implementation)block to implement methods for the Rectangle struct.

Inside the implementation block, we define a method named area that calculates the area of the rectangle.

&self means it borrows the rectangle instance immutably.

self.width and self.height are the fields of the rectangle instance.

It allows us to read width and height without taking ownership or modifying them.

Inside the main function, a new instance of Rectangle is created with, Width = 30 and height = 50.

Save the Program.

It prints “The area of the rectangle is 1500”

Summary

In this tutorial, we learn about

Let us summarize.

Assignment

• Create a tuple named person with the following values:
• Print each value in the tuple using indexing
• Destructure the tuple into separate variables and print those variables.

Thank You