From: Rick DeNatale <rick.denatale@...>
Date: 2007-03-20T02:25:06+09:00
Subject: Re: Sorting Dates and Times in an array

On 3/19/07, Paul <tester.paul@gmail.com> wrote:
> Hi there.  I am having a bit of trouble trying to solve a particular
> sorting problem with an array of data.
>
> Please bear with me for a moment regarding the setup of this problem.
> I don't currently have any control over the input data.  I am just
> trying to format the report of this data as per the requirement.
>
> I have the following sample array data to work with:
> @date_array = [['2/22/07','1:03 pm'],['3/9/07','10:45 pm'],
> ['3/1/07','1:52 pm'],['3/13/07','2:00 pm'],['2/28/07','10:45 am'],
> ['3/5/07','4:00 pm'],['2/14/07','5:00 pm'],['3/9/07','10:18 am'],
> ['3/13/07','11:15 am']]
>
> (The actual array contains more data, but this is good enough to work
> on this problem.  BTW, date format = mm/dd/yy.)
>
> Requirement:
> 1) Sort in descending order by Date (i.e. @date_array[x][0] )
> 2) Sort in ascending order by Time (i.e. @date_array[x][1] )

(Standard Library) objects are your friend.

rick@frodo:/public/rubyscripts$ cat datesort.rb
date_array = [['2/22/07','1:03 pm'],['3/9/07','10:45 pm'],
  ['3/1/07','1:52 pm'],['3/13/07','2:00 pm'],['2/28/07','10:45 am'],
  ['3/5/07','4:00 pm'],['2/14/07','5:00 pm'],['3/9/07','10:18 am'],
  ['3/13/07','11:15 am']]

p date_array.sort do |a, b|
  ddiff = Date.parse(b[0],true) <=> Date.parse(a[0],true)
  ddiff == 0 ? Time.parse(a[0]) <=> Time.parse(b[0]) : ddiff
end

rick@frodo:/public/rubyscripts$ ruby datesort.rb
[["2/14/07", "5:00 pm"], ["2/22/07", "1:03 pm"], ["2/28/07", "10:45
am"], ["3/1/07", "1:52 pm"], ["3/13/07", "11:15 am"], ["3/13/07",
"2:00 pm"], ["3/5/07", "4:00 pm"], ["3/9/07", "10:18 am"], ["3/9/07",
"10:45 pm"]]
rick@frodo:/public/rubyscripts$


-- 
Rick DeNatale

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