From: Justin To Date: 2008-06-07T08:54:44+09:00 Subject: Re: Arrays modArr = Array.new freq = Array.new([ [0] ]) values = Array.new([ [] ]) #--------------Open the output file and process each line----- File.open('output.txt', 'r').each { |x| #-------------Create unique keys according to |x|--------------- #--Calculate the modulus ([add each digit]%10) and use it as hash key-- key = 0; modF = x.each_byte { |y| key += y.chr.to_i } #--For slight optimization, change the resulting key into a symbol mod = (key%100).to_s.intern if(!modArr.include?(mod)) #--Add the value values[modArr.size].push(x.chomp) #--Add the frequency freq[modArr.size].push(1) #--Add the mod modArr.push(mod) end } BLANK.rb:22: undefined method `push' for nil:NilClass (NoMethodError) from BLANK.rb:7:in `each' from BLANK.rb:7 ?? -- Posted via http://www.ruby-forum.com/.