Data Types

Every value in Rust is of a certain data type, which tells Rust what kind of data is being specified so it knows how to work with that data.

Data Types in Rust:

1. Scalar
2. Integers
   • (i8 | u8) - 8-bit Integer
   • (i16 | u16) - 16-bit Integer
   • (i32 | u32) - 32-bit Integer
   • (i64 | u64) - 64-bit Integer
   • (i128 | u128) - 128-bit Integer
   • (isize | usize) - Integer size depends upon the system architecture.
3. Floating Point Numbers
   • f32 - Single-precision 32-bit floating point numbers
   • f64(default) - Single-precision 64-bit floating point numbers
4. Booleans
   • true
   • false
5. Characters
   • char - 4-bytes in size. Capable of holding an Unicode Scalar Value(including Chinese, Japanese, and Korean characters; emoji; and zero-width spaces etc)
6. Compound
7. Tuple
8. Array

Tuple

General way of grouping togather a number of values with variety of types.

fn main() {
  let tup: (i32, f64, u8) = (500, 5.2, 1);

  // accessing values
  // destructuring method
  let (x, y, z) = tup;  // x = 500, y = 5.2, z = 1

  // `access by index` method
  let five_hun = tup.0;
  let float5_2 = tup.1;
  let one = tup.2;
}

Array

Array stores collections of multiple values, but of same type.

fn main() {
  // declaring an array
  let a = [1, 3, 4, 6, 5];
  let b: [i32, 3] = [1, 4, 2];  // array of size 3 of type `i32`
  let c = [4, 10];    // array of size `10` containing same value, i.e. `4`

  // accessing an array
  const firstValue = a[0];
  const secondValue = a[1];

  // main panic
  const valueDoesNotExists = a[400];
}

Accessing an element of an array which is past the end of the array, would result an index out of bounds error, which in result would panic the main thread. This gives a more safe memory access, as the program won't be able to access invalid memory location.

Notes

1. Always check if index of an array which is supposed to be accessed, is less than the length of the array. Otherwise, main thread would panic.