Summary of Rust Methods

Introduction to Methods

In Rust, methods are functions that are associated with a particular type (struct, enum, etc.). They provide a way to define behavior that is specific to the data type.

Key Concepts

• Methods vs. Functions:
  • Methods are defined within the context of a type and can access its data.
  • Functions are standalone and do not have access to the type's data unless passed in.
• Defining Methods:
  • Use the impl keyword to define methods for a type.
  • The first parameter of a method is always &self, which represents the instance of the type.

Example of Method Definition

struct Circle {
    radius: f64,
}

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

Calling Methods

To call a method, simply use the dot notation on an instance of the type.

Example of Method Call

fn main() {
    let circle = Circle { radius: 2.0 };
    println!("Area: {}", circle.area());
}

Method Types

Methods can also take parameters and return values, just like functions.

Example of Methods with Parameters

impl Circle {
    fn circumference(&self) -> f64 {
        2.0 * std::f64::consts::PI * self.radius
    }
}

Summary

• Methods in Rust are a way to define behavior for types.
• They allow encapsulation of functionality and access to the type’s data.
• Use the impl keyword to associate methods with a type.
• Call methods using dot notation on instances of the type.

By understanding these concepts, beginners can effectively use methods to enhance their Rust programming skills.