Data types in Rust

Learn what data types are available in Rust.
It also has two subsets: a scalar data type and a compound data type.

Rust is a statically typed language. It must know the data type of each variable at compile time.

Scalar types

A scalar type used for single value.
Rust has four scalar types (primary):

integers
floating-point numbers
Booleans
and characters.

Find more detail here

Compound types

A compound types can represents group of multiple values.
Rust has 2 primitive compound types:

Tuples

A group of values with different types can be compounded into a tuple.

tuples have a fixed length (they can’t be change)

let tup: (i32, f64, u8) = (500, 6.4, 1); //explicit
let tup = (500, 6.4, 1); //simple

How to get value from a tuple (destructing way)

let (x, y, z) = tup;

How to get value from a tuple (by index/index) by (name(dot)order)

let x: (i32, f64, u8) = (500, 6.4, 1); 
let five_hundred = x.0; 
let six_point_four = x.1; 
let one = x.2;

Array

A group of values with same type.

length is fixed
It’s useful when you want data allocated on the stack rather than the heap (on other chapter)

How to declare an array

let a = [1, 2, 3, 4, 5];
//or
let months = ["January", "February", "March", "April", "May", "June", "July",
              "August", "September", "October", "November", "December"];

If you want a flexible number of items (length can grow or shrink, use vector)

Declare array with same value

let a = [3; 5];

same as

let a = [3, 3, 3, 3, 3];

How to access array element

Using the index in square bracket

let a = [1, 2, 3, 4, 5]; 
let first = a[0]; 
let second = a[1];