Rust Program: Rectangle area calculation

Last update on December 21 2024 10:18:46 (UTC/GMT +8 hours)

Write a Rust program that defines a struct Rectangle with fields width and height. Write a function to calculate the area of a rectangle instance.

Sample Solution:

Rust Code:

// Define a struct named 'Rectangle' with fields 'width' and 'height'
struct Rectangle {
    width: f64,
    height: f64,
}

// Implementation block for the 'Rectangle' struct
impl Rectangle {
    // Define a method named 'area' that calculates the area of a rectangle instance
    fn area(&self) -> f64 {
        self.width * self.height // Calculate the area by multiplying the width and height
    }
}

fn main() {
    let rect1 = Rectangle { width: 5.0, height: 10.0 }; // Create an instance of 'Rectangle'

    // Call the 'area' method on 'rect1' to calculate its area
    let area_of_rect1 = rect1.area();

    // Print the calculated area
    println!("Area of the rectangle: {}", area_of_rect1);
}

Output:

Area of the rectangle: 50

Explanation:

Here is a brief explanation of the above Rust code:

• struct Rectangle { ... }: Defines a struct named "Rectangle" with two fields: 'width' and 'height', both of type 'f64'.
• impl Rectangle { ... }: Begins an implementation block for the "Rectangle" struct.
• fn area(&self) -> f64 { ... }: Defines a method named "area" that takes a reference to 'self' (an instance of "Rectangle") and returns the calculated area as a 'f64'. The method does not take ownership of 'self', so it can be called on immutable references to "Rectangle" instances.
• Inside the "area" method:
• The rectangle's area is calculated by multiplying its 'width' and 'height' fields.
• In the main function,
• An instance of "Rectangle" named 'rect1' is created with 'width' 5.0 and 'height' 10.0.
• The "area" method is called on 'rect1' to calculate its area, and the result is stored in 'area_of_rect1'.
• The calculated area is printed to the console.

Rust Code Editor:

Previous: Rust Structs and Enums Exercises.
Next: Rust Program: Enum Direction.