Elixir: what is the meaning of nil

Question

我正在学习灵丹妙药，我想知道在JavaScript中nil是否与null相同，如果不是，那是什么意思？

Answer 1

They are similar, both are often used to denote the absence of a value. In JavaScript, !!null evaluates to false , while in Elixir, !!nil evaluates to false . Just like JavaScripts null , you can use nil as a "falsy" value in a boolean context, for instance:

if nil do
  IO.puts "foo"
else
  IO.puts "bar"
end

will print "bar"

I can't think of many differences between the two, other than perhaps a few corner cases. For instance, null > 0 evaluates to false in JavaScript, while nil > 0 evaluates to true in Elixir.