From: "Jesús Gabriel y Galán" <jgabrielygalan@...>
Date: 2011-04-20T16:49:38+09:00
Subject: Re: Can I check contain value in hash?

On Wed, Apr 20, 2011 at 6:02 AM, Siratinee Sukachai
<ploy.sukachai@gmail.com> wrote:
> I have hash which is contain list of string value.
> I need to check is the value already contained in the key.
> Add add the value to the key if the key is not contained that value.
> Can I do that?
>
> like in c#
>
> if(!dict[key].contains(value))
> {
>  dict[key].add(value);
> }

You can try the code. A similar approach to the c# above could use
methods Hash#has_key?
(http://ruby-doc.org/core-1.8.7/classes/Hash.html#M000515),
Array#include (http://ruby-doc.org/core-1.8.7/classes/Array.html#M000343)
and Array#<< (http://ruby-doc.org/core-1.8.7/classes/Array.html#M000306).

Although if your arrays can grow and so you are checking include? many
times on big arrays, you might want to use a Set instead of an Array.

Jesus.