What does ? do in Elixir

Question

I am aware of String.strip/2 , but I cannot figure out its usage for removing whitespaces.

String.strip "_some_", ?_   #=> "some"

If the string had whitespaces instead of _, how does one strip them? Also, it would be great if someone can explain what ? means here.

Answer 1

字符前面的问号返回其代码点，它在入门指南的这一部分中提到： http ： //elixir-lang.org/getting-started/binaries-strings-and-char-lists.html

Answer 2

There's String.strip/1 which strips all unicode whitespace. So you can just

iex(2)> String.strip("\t\ntest   ")
"test"