From: Stefan Rusterholz <apeiros@...>
Date: 2007-08-19T10:34:40+09:00
Subject: Re: Adding to an array question

Corey Haines wrote:
> I need to add a string to the end of an array count number of times. I
> was wondering if I could get some advice on the prefered way to do it
> in Ruby.
> 
> @bucket is the array
> 
> 
> def add_person(count, name)
>  @bucket += Array.new(count, name)
> end
> 
> or some other ideas
> 
> def add_person(count, name)
> count.times {@bucket << name }
> end
> # or some variation of looping
> 
> Personally, I like the adding a new array to the @bucket array. I
> realize (at least I assume) that it creates a temporary Array, but I
> think it is more understandable?
> 
> Thoughts?
> Thanks, I'm just learning Ruby
> -Corey

def add_person(name, count=1) # I assume adding once as a default is 
rather safe
  @bucket.concat(Array.new(count) { name.dup }) # a) this will create a 
new string object everytime
  @bucket.concat(Array.new(count, name) # b) this will use the *same* 
string object everytime
end

Use either a) or b). Be aware that with b) if you do e.g. 
@bucket.last.upcase!, it will reflect on all slots that contain the same 
object.
As to why I prefer this concat solution over array +=: it doesn't create 
throw away objects everytime.

Regards
Stefan
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