Methods of Structs

• What Are Methods?

Methods are just like user-defined functions. They are like functions, but the only difference lies in the fact that methods are declared specifically within the struct context.

• Declare a Method

The method is like a regular function except that the &self parameter is passed to it and the items within the function are accessed through it.

self.ite

Here self is the calling instance, i.e., it is referencing to the struct.

• Call a Method

An instance of the struct has to be created to invoke it. This is similar to invoking a struct.

Why struct method? The main advantage is that all the data related to the instance is put inside the impl block rather than putting it in different places.

# Example

The example below shows declares a method name_code function within the impl construct:

//declare a struct

struct Course {

    name: String,

    level: String,

    code:i32

}

//impl construct to define struct methods

impl Course {

    fn name_code(&self) -> String {

        format!("{} {}", self.name, self.code)

    }

}



fn main() {

    let course_1 = Course {

        name: "Rust".to_string(),

        level:"beginner".to_string(),

        code:132

    };

    //call the non-static method

    println!("This is a {} course: {}", course_1.level, course_1.name_code());

}

output

This is a beginner course: Rust 132

Quiz

Test your understanding of methods of structs.

1. Which code block has the method enclosed in it?
   A) impl
   B) fn