Scope and Constants in #Rust

constants_and_scope.rs

#[allow(dead_code)]
#[allow(unused_variables)]

fn main() {
    scope_and_shadowing();
    constnts();
}

fn scope_and_shadowing() {
    let age = 23;

    {
        let age = 34;
        println!("Child age = {}", age);
    }
    println!("Parent age = {}", age);
}

const AVERAGE_AGE : u8 = 60;   // no fixed address
static  PREFIX : char = 'A';  // fixed address
static  mut AGE : u8 = 22;   // mutable fixed address

fn constnts() {
    println!("Average age is {}", AVERAGE_AGE);
    println!("Prefix character is {}", PREFIX);

    unsafe {
        println!("Age earlier was {}", AGE);
        AGE = 59;
        println!("Age now is {}", AGE);
    }
}