From: "Rüdiger Brahns" <ruedi@...>
Date: 2008-10-12T23:37:30+09:00
Subject: Re: Compare Arrays

Todd Benson schrieb:
> On Sat, Oct 11, 2008 at 10:50 PM, Tj Superfly <nonstickglue@verizon.net> wrote:
>> Hey, I just have a quick question about arrays.
>>
>> I have two different ones that I would like to compare.
>>
>> Example:
>>
>> Array 1: cats, dogs, monkeys
>>
>> Array 2: cats, fish, dogs, birds, monkeys
>>
>> Now, I would like to compare array 2 with array 1 and have it spit out
>> any words that aren't in both... if that makes sense.
>>
>> So what the program should output is fish, monkeys.
> 
> Hmm.  I'm assuming you are looking for ["fish", "birds"], and if you
> are, do union, then subtract intersection...
> 
> a = %w( cats dogs monkeys )
> b = %w( cats fish dogs birds monkeys )
> 
> (a | b) - (a & b)

Why not just

b - a

? But as I understand him what he wants is

a & b