From: Paul Smith <paul@...>
Date: 2009-09-26T00:52:47+09:00
Subject: Re: How to remove duplicate elements in a 2D array

On Fri, Sep 25, 2009 at 4:39 PM, Paul Smith <paul@pollyandpaul.co.uk> wrote:
> On Fri, Sep 25, 2009 at 4:34 PM, Li Chen <chen_li3@yahoo.com> wrote:
>> Hi all,
>>
>> I have a 2D array as follow:
>>
>> arr=[
>>
>>     [ 'a',1,2,3],
>>     ['b',4,5,6],
>>     ['c',3,2,1],
>>     ['a',1.3,2.2,3,3],
>>     ...
>>     ['a', 2,1,3],
>>   ...
>>   ['a',2.1,1.5,3]
>>
>> ]
>>
>> As you can see there are several rows containing  element 'a',
>> and the last row containing 'a'' is the lastest one.  I wonder if it
>> is possible to return a new array which contains the latest row having
>> 'a' ,
>> together with other rows.
>
> result = []
> arr.each { |x| result = x if x[0] == 'a' }
> result
>
> ?

Sorry, this only solves the "Last row containing a" part of the
problem.  If you're intending to eliminate duplicates, then use that
first element as the key to a hash.

result = {}
arr.each{|x| result[x[0]] = x[1,x.length-1]}

?

>
> --
> Paul Smith
> http://www.nomadicfun.co.uk
>
> paul@pollyandpaul.co.uk
>
>



-- 
Paul Smith
http://www.nomadicfun.co.uk

paul@pollyandpaul.co.uk