Remove duplicates from loop

Question

i have following code.

for i in 0..sold.length-1
    duplicate = sold[i]
    print duplicate.check_duplicates
    print \"     \"
    print sold[i].lotnumber + \         


        

Answer 1

uniq_solds = sold.collect{|s| [s.check_duplicates, s.lotnumber, s.serialnumber]}.uniq

uniq_solds.each do |s|
  p s.join("      ")
end

Answer 2

You can try using something called uniq!, here is a link to the API.

http://www.ruby-doc.org/core-2.0.0/Array.html#method-i-uniq-21

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Answer 3

The hash resulting from the group_by method can be used as a counting device; this does not use the check_duplicates method.

grouped = sold.group_by{|item| [item.lotnumber, item.serialnumber]}
grouped.each{|key, value| puts "#{value.size}   #{key.first}\t#{key.last}"}