I want to test whether a equals 1 or 2
I could do
a == 1 || a == 2
but this requires repeating a (which would be annoying for longer variables)
I'd like to do something like a == (1 || 2), but obviously this won't work
I could do [1, 2].include?(a), which is not bad, but strikes me as a bit harder to read
Just wondering how do to this with idiomatic ruby
Your first method is idiomatic Ruby. Unfortunately Ruby doesn't have an equivalent of Python's a in [1,2], which I think would be nicer. Your [1,2].include? a is the nearest alternative, and I think it's a little backwards from the most natural way.
Of course, if you use this a lot, you could do this:
class Object
def member_of? container
container.include? self
end
end
and then you can do a.member_of? [1, 2].
I don't know in what context you're using this in, but if it fits into a switch statement you can do:
a = 1
case a
when 1, 2
puts a
end
Some other benefits is that when uses the case equality === operator, so if you want, you can override that method for different behavior. Another, is that you can also use ranges with it too if that meets your use case:
when 1..5, 7, 10
First put this somewhere:
class Either < Array
def ==(other)
self.include? other
end
end
def either(*these)
Either[*these]
end
Then, then:
if (either 1, 2) == a
puts "(i'm just having fun)"
end