truthiness.rb(main):001:0> #! /usr/bin/env ruby
truthiness.rb(main):002:0* 
truthiness.rb(main):003:0* values = [ true, false, 1, 0, -1, 'some string', '', nil ]
=> [true, false, 1, 0, -1, "some string", "", nil]
truthiness.rb(main):004:0> 
truthiness.rb(main):005:0* values.each do |val|
truthiness.rb(main):006:1* 	text = if val == nil then "nil" else "'#{val}'" end
truthiness.rb(main):007:1> 	puts "Val #{text} is truthy" if val
truthiness.rb(main):008:1> 	puts "Val #{text} is falsy" unless val
truthiness.rb(main):009:1> end
Val 'true' is truthy
Val 'false' is falsy
Val '1' is truthy
Val '0' is truthy
Val '-1' is truthy
Val 'some string' is truthy
Val '' is truthy
Val nil is falsy
=> [true, false, 1, 0, -1, "some string", "", nil]
truthiness.rb(main):010:0>