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];