Functions

November 14, 2022

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Functions in Rust are defined with fn. The function name and its input arguments should be lowercase with underscores to separate words. Some examples of functions are shown below.

fn main() {

    basic_function();

    let sum = adder(2, 3);
    println!("The sum is {sum}");

    let frac = divider(5.0, 2.0);
    println!("The fraction is {frac}");
}

// A basic function with no inputs

fn basic_function() {
    println!("Basic function with no inputs");
}

// Use the return keyword to return a value

fn adder(x: i32, y: i32) -> i32 {
    let s = x + y;
    return s
}

// This function uses an expression to return its value. Notice the absence of
// a semicolon after the expression in the function.

fn divider(x: f32, y: f32) -> f32 {
    x / y
}