Sorting a hash based on a attribute of teh objects which it


#1

HI all,
I want to sort a hash based on a attribute of the objects which it
is storing.For example i am having a bean diagnosis with weightage as a
attribute.i want to sort the hash of diagnosis based on the
weightage.how to do this .
can any one explain me …

thanks and regards,
senthil kumar


#2

senthil schrieb:

HI all,
I want to sort a hash based on a attribute of the objects which it
is storing.For example i am having a bean diagnosis with weightage as a
attribute.i want to sort the hash of diagnosis based on the
weightage.how to do this .
can any one explain me …

thanks and regards,
senthil kumar

Here is all you need:
http://www.oreillynet.com/ruby/blog/2005/12/sorting_an_array_of_hashes_wit_2.html


#3

On 3/13/07, senthil removed_email_address@domain.invalid wrote:


Posted via http://www.ruby-forum.com/.

Hashes do not define any order by definition (in Ruby), please search
the list for implementations of “ordered Maps/Dictionaries/Hashes”
this is a VFAQ.

If you can take the time to convert your hash to a sorted array of
pairs you can something like this of course.

hash.to_a.sort{ |h1, h2|
h1.first.whatever <=> h2.first.whatever # for keys
or
h1.last.whatelse <=> h2.last.whateles # for values
}

HTH
Robert


#4

On Mar 13, 2007, at 5:45 AM, senthil wrote:

HI all,
I want to sort a hash based on a attribute of the objects
which it
is storing.For example i am having a bean diagnosis with weightage
as a
attribute.i want to sort the hash of diagnosis based on the
weightage.how to do this .
can any one explain me …

Hashes themselves aren’t sorted so you have to extract the
objects and then sort that list:

class Beans < Struct.new(:description, :weightage); end

b1 = Beans.new(‘bean 1’, 20)
b2 = Beans.new(‘bean 2’, 30)
b3 = Beans.new(‘bean 3’, 25)

collection = { b1.description => b1, b2.description => b2,
b3.description => b3}

sorted = collection.values.sort_by { |x| x.weightage }
p sorted

[#<struct Beans description=“bean 1”, weightage=20>, #<struct Beans
description=“bean 3”, weightage=25>, #<struct Beans description=“bean
2”, weightage=30>]

P.S. What is a ‘bean diagnosis’ and ‘weightage’?

Gary W.


#5

Gary W. wrote:

On Mar 13, 2007, at 5:45 AM, senthil wrote:

HI all,
I want to sort a hash based on a attribute of the objects which it
is storing.For example i am having a bean diagnosis with weightage as a
attribute.i want to sort the hash of diagnosis based on the
weightage.how to do this .

P.S. What is a ‘bean diagnosis’ and ‘weightage’?

Quality control in the Jelly Belly factory?