Elixir: when to use 'number' and when to use 'integer'

Question

The examples seem to consist of both 'number' and 'integer'. What are the respective situations that they should be used in?

Edit: here is an example of each

@type bar :: %{atom => [{binary, integer}]}

def foo(x) when is_number(x), do: x

Answer 1

Number is a more general type which refers to both floats and integers. If you want to check if a value is numeric, but don't care if it's a float or an integer, use number. If you want to enforce a specific type, use integer/float. In your example above you could use is_integer(x) or is_float(x) instead of is_number(x) if you need more specificity.