As someone who isnt a programmer, why are those "guides" done so poorly? def double(val) val + val end The example does not show what happens when you try t

As someone who isnt a programmer, why are those "guides" done so poorly? def double(val) val + val end The example does not show what happens when you try to connect text and a number. Will it glue them together? Give an error? Also, "for humans", the whole x = x + 1 is illogical.