Basic Types & Variables

• bool - Boolean

• Unsigned integers

  u8, u16, u32, u64, u128

• Signed integers,rust

  i8, i16, i32, i64, i128
  

• Floating point numbers

  f32, f64
  

• Platform specific integers

  • usize - Unsigned integer. Same number of bits as the platform's pointer type.
  • isize - Signed integer. Same number of bits as the platform's pointer type.
  • char - Unicode scalar value
  • &str - String slice
  • String - Owned string

Tuple

let coordinates = (82, 64);
let score = ("Team A", 12);

Array & Slice

• Arrays must have a known length and all elements must be initialized

• Unlike arrays the length of a slice is determined at runtime

let array = [1, 2, 3, 4, 5];
let array2 = [0; 3]; // [0, 0, 0]
let slice = &array[1 .. 3];

HashMap

use std::collections::HashMap;
let mut subs = HashMap::new();
subs.insert(String::from("Rust"), 100000);

// Insert key if it doesn't have a value

subs.entry("Golang".to_owned())
    .or_insert(3);

Struct

• Definition

struct User {
    username: String,
    active: bool,
}

• Instantiation

let user1 = User {
    username: String::from("bogdan"),
    active: true,
};

• Tuple struct

struct Color(i32, i32, i32);
let black = Color(0, 0, 0);

Enum

• Definition

enum Command {
    Quit,
    Move { x: i32, y: i32 },
    Speak(String),
    ChangeBGColor(i32, i32, i32),
}

• Instantiation

let msg1 = Command::Quit;
let msg2 = Command::Move{ x: 1, y: 2 };
let msg3 = Command::Speak("Hi".to_owned());
let msg4 = Command::ChangeBGColor(0, 0, 0);

Constant

const MAX_POINTS: u32 = 100_000;

Static variable

• Unlike constants static variables are stored in a dedicated memory location and can be mutated.

static MAJOR_VERSION: u32 = 1;
static mut COUNTER: u32 = 0;

Mutability

let mut x = 5;
x = 6;

Shadowing

let x = 5;
let x = x * 2;

Type alias

• NanoSecond is a new name for u64.

type NanoSecond = u64;