Wilson Bilkovich
1/16/2007 5:33:00 PM
On 1/16/07, David Madden <moose56@gmail.com> wrote:
> I am playing with an example in the ruby cookbook where a shuffle
> function is added to the array class:
>
> class Array
>
> def shuffle!
> each_index do |i|
> j = rand(length-i) + i
> self[j], self[i] = self[i], self[j]
> end
> end
>
> def shuffle
> dup.shuffle!
> end
>
> end
>
> What I don't understand is the line "dup.shuffle!"
>
> What is the dup object?
>
dup returns a copy (duplicate) of the object. In the above code, it is
used to let you get back a shuffled copy of the Array, without
shuffling the original.
type:
ri Object#dup
for more info.