Check if array contains more nils than other values - arrays

Question

Given an array with only odd counts:
[1,nil,nil]
[1,nil,Module,nil,2]
[1,Class.new,nil]
I would like to determine if there are nils or more non-nils. The approach I used was to make everything either true or false first. And then to determine if there are more true or false values:
[ 1,nil,nil,nil,2,3].collect {|val| !!!val }.max
#=> ArgumentError: comparison of TrueClass with false failed
The max method does not want to play nice with booleans. How can I accomplish this?
Now this might not be the best approach to determine whether there are more nils or non-nils, but this is the approach that I used.

Answer 1

Given an array with only odd counts
If by that you mean that there will always be the nonequal amount of truthy/falsey values in an array, then, first of all, [] is not a valid input.
And here's the solution:
def truthy?(array)
falsey, truthy = array.partition(&:!)
truthy.size > falsey.size
end
You can go with oneliner if you prefer:
def truthy?(array)
array.partition(&:!).max_by(&:size).any?
end
Spec:
truthy?([1,nil,nil]) #=> false
truthy?([1,nil,nil,nil,2]) #=> false
truthy?([1,4,nil]) #=> true
truthy?([1,nil,nil]) #=> false
truthy?([1,nil,Module,nil,2]) #=> true
truthy?([1,Class.new,nil]) #=> true
It uses
Enumerable#partition method;
BasicObject#! method.
If you indeed intended to only calculate nils, not falsey values (as it was stated in the OP):
def more_nils?(array)
array.partition(&:nil?).max_by(&:size).none?
end
Spec:
more_nils?([1,nil,nil]) #=> true
more_nils?([1,nil,nil,nil,2]) #=> true
more_nils?([1,4,nil]) #=> false
more_nils?([1,nil,nil]) #=> true
more_nils?([1,nil,Module,nil,2]) #=> false
more_nils?([1,Class.new,nil]) #=> false
It uses Object#nil? method.
Inspired by #pjs's answer:
array.sum { |el| el.nil? ? -1 : 1 }.negative?
Even simpler ( from #SagarPandya's comment)
array.count(nil) > array.compact.count

Answer 2

A fairly straightforward solution would be:
def truthy?(ary)
ary.map { |bool| bool ? 1 : -1 }.sum > 0
end
Map entries to +/-1 based on their truthiness, sum, and see whether the sum is positive or negative.
This can deal with empty arrays, it returns false in that case.

Answer 3

Here another one:
if array.size > 2*array.compact.size
# We have more nil than non-nil
end

Answer 4

Assuming that falsy values are nil and false, and everything else is truthy (as conditional statements do), you can leverage Object#itself with Array#select.
irb(main):013:0> ary = [1,nil,nil,false,2]
=> [1, nil, nil, false, 2]
irb(main):014:0> ary.select(&:itself).length
=> 2
irb(main):015:0> ary.reject(&:itself).length
=> 3