From: Stefan Lang <perfectly.normal.hacker@...>
Date: 2008-03-05T21:05:54+09:00
Subject: Re: collect with index?

2008/3/5, Tim Conner <plump4651@googlemail.com>:
> simple question:  how can I do a collect with index?  This should be
>  like each_with_index but should return a new array containing the values
>  returned by the block.
>  i.e
>  Say i want to return:
>  ["cat number 1","dog number 2","pig number 3"
>
>  how would i do this?  I am thinking that there must be something along
>  the lines of:
>  %w{"cat","dog","pig"}.collect_with_index {|animal,index| animal+" number
>  "+index}

    >> require "enumerator"
    => true
    >> ary = ["cat", "dog", "pig"]
    => ["cat", "dog", "pig"]
    >> ary.enum_for(:each_with_index).collect { |animal, index|
         "#{animal} number #{index + 1}"
       }
    => ["cat number 1", "dog number 2", "pig number 3"]

Or in Ruby 1.9 it's simply:

    >> ary = ["cat", "dog", "pig"]
    => ["cat", "dog", "pig"]
    >> ary.each_with_index.collect { |animal, index|
         "#{animal} number #{index + 1}"
       }
    => ["cat number 1", "dog number 2", "pig number 3"]


HTH,
  Stefan