From: Mike Moore <blowmage@...>
Date: 2011-03-04T02:38:45+09:00
Subject: Re: How to assign an element to a hash only if its value is not nil?

On Thu, Mar 3, 2011 at 10:10 AM, Thomas W. <thomas@thomas-witt.com> wrote:
>
> hash = {}
>    hash[:key] = myvalue
>
>
> How to assign hash[:key] only if myvalue is not nil?
>
> Current solution is:
>
>    hash[:key] = myvalue unless myvalue.nil?
>
>
> Is there something more beautiful?

You could assign the all values and then remove the just the nil
values afterward.

  >> h = { :one => 1, :two => 2, :three => nil, :four => 4, :five => nil }
  => {:three=>nil, :four=>4, :five=>nil, :one=>1, :two=>2}
  >> h[:six] = 6
  => 6
  >> h[:seven] = nil
  => nil
  >> h.delete_if { |k, v| v.nil? }
  => {:four=>4, :six=>6, :one=>1, :two=>2}