Code Exploder

Elixir Basic Arithmetic

August 24, 2018

This blog post is about Elixir basic types and arithmetic. Elixir basic types: integers, floats, booleans, atoms, strings, lists and tuples. Some basic types are:

iex> 1          # integer
iex> 0x1F       # integer
iex> 1.0        # float
iex> true       # boolean
iex> :atom      # atom / symbol
iex> "elixir"   # string
iex> [1, 2, 3]  # list
iex> {1, 2, 3}  # tuple

Basic Arithmetic

iex> 1 + 2
3
iex> 5 * 5
25
iex> 10 / 2
5.0

Notice that 10 / 2 returned a float 5.0 instead of an integer 5. This is expected. In Elixir, the operator / always returns a float. If you want to do integer division or get the division remainder, you can invoke the div and rem functions:

iex> div(10, 2)
5
iex> div 10, 2
5
iex> rem 10, 3
1

Notice that Elixir allows you to drop the parentheses when invoking named functions. This feature gives a cleaner syntax when writing declarations and control-flow constructs.

Elixir also supports shortcut notations for entering binary, octal, and hexadecimal numbers

iex> 0b1010
10
iex> 0o777
511
iex> 0x1F
31

Float numbers require a dot followed by at least one digit and also support e for scientific notation:

iex> 1.0
1.0
iex> 1.0e-10
1.0e-10

Floats in Elixir are 64-bit double precision.

You can invoke the round function to get the closest integer to a given float, or the trunc function to get the integer part of a float.

iex> round(3.58)
4
iex> trunc(3.58)
3

Written by Tianyi Wang who lives and works in Dublin Ireland building things. You should follow him on Twitter