Rework if/2 docs and mention variable scope #14452
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sorentwo
reviewed
Apr 26, 2025
Co-authored-by: Parker Selbert <[email protected]>
dmitrykleymenov
suggested changes
Apr 26, 2025
lib/elixir/lib/kernel.ex
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| @@ -3898,51 +3898,63 @@ defmodule Kernel do | |||
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| ## One-liner examples | |||
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| if(foo, do: bar) | |||
| iex> if 7 > 5, do: "yes" | |||
| "yes" | |||
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| In the example above, `bar` will be returned if `foo` evaluates to | |||
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In the example above, "yes" is returned because 7 > 5 evaluates to a truthy value (true in this case). nil will be returned if the condition evaluates to a falsy(nil or false) value:
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Thanks @dmitrykleymenov, good catch!
Fixed in 96bbccf
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I'm just curious if it should be mentioned that the code inside unmatched blocks isn't even evaluated, and it's not only about a return value. |
It's true that it wasn't explicitly called out, added an example in 6d56287 |
josevalim
reviewed
Apr 26, 2025
josevalim
approved these changes
Apr 26, 2025
Co-authored-by: José Valim <[email protected]>
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The structure of the
ifdoc was a bit hard to understand, since:nilwill bereturned.")
if(foo, do: bar)andif foo, do: barform, but AFAIK the former is less common and idiomatic nowadays?I also noticed that the fact we can define a variable in the
ifcondition wasn't explicitly documented, as well as scope rules more broadly (even if they aren't specific toif, it's probably the more common place people encounter it). Inspired from this