What is the opposite method of Array.empty? or [].empty? in ruby
RubyRuby Problem Overview
I do realize that I can do
unless [1].empty?
But I'm wondering if there is a method?
Ruby Solutions
Solution 1 - Ruby
As well as #any? as davidrac mentioned, with ActiveSupport there's #present? which acts more like a truth test in other languages. For nil, false, '', {}, [] and so on it returns false; for everything else true (including 0, interestingly).
Solution 2 - Ruby
You may use [1].any?, which is actually defined in Enumerable
Note that this will not work in case your array hold only nil or false values.
Solution 3 - Ruby
[nil].any?
=> false
[nil].any? {|something| true}
=> true
[].any? {|something| true}
=> false
[false, false].any? {|something| true}
=> true
[nil, 'g'].any? {|something| true}
=> true
Solution 4 - Ruby
No single method I know of is going to give you that in Ruby. Key word 'single':
[5].size.positive? => true
[5].size.nonzero? => 1
[].size.positive? => false
[].size.nonzero? => nil
Both of these are even more useful with the safe navigation operator, since nil returns falsy, meaning negative methods (like #empty?) break down a bit:
# nil considered 'not empty' isn't usually what you want
not_empty = proc{|obj| !obj&.empty? }
not_empty.call nil => true
not_empty.call [ ] => false
not_empty.call [5] => true
# gives different 3 answers for the 3 cases
# gives truthy/falsy values you'd probably expect
positive_size = proc{|obj| obj&.size&.positive? }
positive_size.call nil => nil
positive_size.call [ ] => false
positive_size.call [5] => true
# gives truthy/falsy values you'd probably expect
nonzero_size = proc{|obj| obj&.size&.nonzero? }
nonzero_size.call nil => nil
nonzero_size.call [ ] => nil
nonzero_size.call [5] => 1
Solution 5 - Ruby
To check for elements in array :
.empty?
.present?
if a={}
a.any? .nil?
will gives you false.
To check whether or not a field has a non-nil value:
.present?
.nil?
.any?