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The ? character in comprehensions

#comprehensions#learning-elixir
tio407

tio407

The ? character in comprehensions

I got an answer right on one of my exercises just by guessing but want to understand Elixir.

Can you help me understand how this piece of code works

  defp converter do
    fn
      ?A -> ?U
      ?C -> ?G
      ?T -> ?A
      ?G -> ?C
    end
  end

I don’t understand the ? character and what it is doing here.

3 comments
#comprehensions#learning-elixir
9 674 3

Marked As Solved

kokolegorille

kokolegorille

It returns the codepoint of the character…

iex> ?a
97

BTW You get the opposite with…

iex> List.to_string [?a]
"a"
4
Post #2

Also Liked

Nicd

Nicd

Another way to get the string out of a codepoint, just for reference:

iex(4)> <<?ƒ::utf8>>
"ƒ"
iex(5)> <<?a::utf8>>
"a"
iex(6)> var = 5356
5356
iex(7)> <<var::utf8>>
"ᓬ"
5
Post #3

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