From: "Marcin Mielżyński" <lopexx@...>
Date: 2006-03-08T23:48:41+09:00
Subject: Re: Newbie: sorting an array of custom objects

Marcin Mielżyński wrote:
> Einar Høst wrote:
>> Hi,
>>
>> As a project for learning Ruby, I'm writing a simple game. I have some 
>> simple objects that I would like to be able to sort 'automatically' in 
>> an array. In Java, I can implement the Comparable interface to make 
>> the Array.sort method do this for me. I'm sure I can do something 
>> similar or simpler i Ruby, I just don't know how. Can anyone help? An 
>> even more elegant solution would be to able to say to the array 'just 
>> put this object where it belongs', without really having to sort the 
>> whole array.
>>
>> Thanks a lot!
>>
>> Kind regards,
>> Einar
> 
> arr.sort_by{|obj| obj.some_field}
> 

there is also another method for array sorting (actually it was the 
first in standard library)

arr.sort{|a,b| a.some_field <=> b.some_field}

if you define <=> operator for your class

def <=> arg
      @some_field <=> arg.some_field
end

ther you will be able to

arr.sort

lopex