Programming Elixir ≥ 1.6

Single-Quoted Strings—Lists of Character Codes

Single-quoted strings are represented as a list of integer values, each value corresponding to a codepoint in the string. For this reason, we refer to them as character lists (or char lists).

iex> str = 'wombat'
'wombat'
iex> is_list str
true
iex> length str
6
iex> Enum.reverse str
'tabmow'

This is confusing: IEx says it is a list, but it shows the value as a string. That’s because IEx prints a list of integers as a string if it believes each number in the list is a printable character. You can try this for yourself:

iex> [ 67, 65, 84 ]
'CAT'

You can look at the internal representation in a number of ways:

iex> str = 'wombat'
'wombat'
iex> :io.format "~w~n"