From: William Rutiser <wruyahoo05@...>
Date: 2010-03-20T22:07:42+09:00
Subject: Re: Version issues

David Vlad wrote:
> I apologize. I actually managed to get the until loops working after 
> some reinstalling. However, the .collect method still dosnt work and I 
> really want to use it. The code looks like this:
>
>
> array = [1,2,5,7]
>
> array.collect do |x|
>  x = x*2
> end
>
> puts array.inspect
>
>
> After I have run this code it still says the array is [1,2,5,7].

"array.collect " isn't supposed to modify array.

"array.collect" returns a newly constructed array containing the block's 
results.

Compare

irb(main):001:0> array = [1,2,5,7]
=> [1, 2, 5, 7]
irb(main):002:0>
irb(main):003:0* array.collect do |x|
irb(main):004:1*  x = x*2
irb(main):005:1> end
=> [2, 4, 10, 14]
irb(main):006:0>
irb(main):007:0* puts array.inspect
[1, 2, 5, 7]
=> nil

with

irb(main):008:0> array = [1,2,5,7]
=> [1, 2, 5, 7]
irb(main):009:0> puts array.collect do |x|
irb(main):010:1*  x = x*2
irb(main):011:1> end
1
2
5
7
=> nil
irb(main):012:0> puts array.inspect
[1, 2, 5, 7]
=> nil