From: Dave Thomas <Dave@...>
Date: 2001-07-13T06:35:04+09:00
Subject: [ruby-talk:17759] Re: What is Array#- ?

Jim Freeze <jim@freeze.org> writes:

> Regardless, if I have 5 apples and 2 pairs and I take away the pairs,
> why do I end up with only 1 apple?

Easy: 5 - 2 pairs is one.  Next  :)

It's just that you can't have 5 apples in a set. They'd need to be in
a bag.

Somewhat confusingly, the opposite of Array#- is array#|, for set
union.

   a = [ ]

   5.times { a = a | [ :apple ] }
   2.times { a = a | [ :pear ] }

   p a   #=>   [ :apple, :pear ]


Regards


Dave