On 10/28/07, Shuaib Zahda <shuaib.zahda / gmail.com> wrote:
> Hello
>
> I am trying to output the duplicate elements in an array. I looked into
> the api of ruby I found uniq method which outputs the array with no
> duplication. What i want is to know which elements is duplicated.
> For example
>
> array = ["apple", "banana", "apple", "orange"]
> => ["apple", "banana", "apple", "orange"]
> array.uniq
> => ["apple", "banana", "orange"]
>
> I want the method to tell me that apple is the duplicated element
>
> I tried this but it does not work
>
> array - array.uniq
>
> any idea
>
> Regards
> Shuaib
> --
> Posted via http://www.ruby-forum.com/.
>
>

arr,dup = ["apple", "banana", "apple", "orange"],[]
(arr.length-1).times do
  a = arr.shift
  dup << a if arr.include?(a)
end
p dup.uniq

Harry

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