hyperion@hyperion:~/rust_material/playground/src$ more main.rs
extern crate rand;

use std::io;
use std::cmp::Ordering;
use rand::Rng;


fn main() {
    let a = 5;
    if a>10{
        println!("true");
    }
    else {
        println!("false");
    }
}

fn display_p(arr : [i32;5]) {
    let a  = {
        let b : i32 = 32;
    };
    println!("{}",a)
}

/*
let er : (i32,f32,char)=(23,23.0,'');
printn;

match a.cmp(&b)
{
    Ordering::Less => println(),
    Ordering::Greater =>,

}
 let a : u32 ="42".len().expect("bot a number");;

 let mut a: u32 =String.new().trim().parse();

data types are as
i8;i16;164
u64,u32;
isize depends on the architecture
usize depends on the arch
rust floating types are defined as
f32 as 32 bit
f64 as 64 bit
let f :bool = false;
char is the most basic and is thus used as it is
let a = 'a';

*/


hyperion@hyperion:~/rust_material/playground/src$ cargo run
   Compiling playground v0.1.0 (/home/hyperion/rust_material/playground)
warning: unused import: `std::io`
 --> src/main.rs:3:5
  |
3 | use std::io;
  |     ^^^^^^^
  |
  = note: #[warn(unused_imports)] on by default

warning: unused import: `std::cmp::Ordering`
 --> src/main.rs:4:5
  |
4 | use std::cmp::Ordering;
  |     ^^^^^^^^^^^^^^^^^^

warning: unused import: `rand::Rng`
 --> src/main.rs:5:5
  |
5 | use rand::Rng;
  |     ^^^^^^^^^

error[E0277]: `()` doesn't implement `std::fmt::Display`
  --> src/main.rs:22:19
   |
22 |     println!("{}",a)
   |                   ^ `()` cannot be formatted with the default formatter
   |
   = help: the trait `std::fmt::Display` is not implemented for `()`
   = note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead
   = note: required by `std::fmt::Display::fmt`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0277`.
error: Could not compile `playground`.

To learn more, run the command again with --verbose.