charlist.rb

chars = [*" ".."~"]

charlist = nil

chars.each do |char|
  charlist << "#{char},"
end

puts charlist

#this is returning

#char_loop.rb:6:in `block in <main>': undefined method `<<' for nil:NilClass (NoMethodError)
#        from char_loop.rb:5:in `each'
#        from char_loop.rb:5:in `<main>'