Functions

• Functions are declared with the keyword fn

• When using arguments, you must declare data types.

• By default functions return empty tuple (). If you want to return a value, return type must be specified after ->

Hello world

fn main() {
    println!("Hello, world!");
}

Passing arguments

fn print_sum(a: i8, b: i8) {
    println!("sum is: {}", a + b);
}

Returning Values

fn plus_one(a: i32) -> i32 {
    a + 1 //no ; means an expression, return a+1
}

fn plus_two(a: i32) -> i32 {
    return a + 2; //return a+2 but bad practice,
    //should use only on conditional returnes, except it's last expression
}

// ⭐️ Function pointers, Usage as a Data Type
let b = plus_one;
let c = b(5); //6

let b: fn(i32) -> i32 = plus_one; //same, with type inference
let c = b(5); //6