From: Harry Kakueki <list.push@...>
Date: 2007-06-18T12:07:43+09:00
Subject: Re: Adding new value (in array) to existing key in a hash

On 6/18/07, Gilbert Lau <gilbertlsk@gmail.com> wrote:
> Thanks a lot. Sorry, got another question
>
> let's say that the hash is
>
> myhash = {"a" => [[0,0],[3,4]], "b" => [[1,1],[9,8]], "c" => [[7,6]]}
>
> how do I sort the values to become
>
> [0,0],[1,1],[3,4],[7,6],[9,8]
>
> and be able to recall the keys to arrange according to the sorted
> values, like
>
> "a", "b", "a", "c", "b"
>

Well, I think this will work.
Extract the arrays from the values and then sort.

myhash = {"a" => [[0,0],[3,4]], "b" => [[1,1],[9,8]], "c" => [[7,6]]}

arr = []
myhash.each_value do |x|
x.each {|y| arr << y}
end

p arr.sort!

# This will find whether it is included in "a" for example
# but you need to think about what to do if you have duplicates.
# myhash = {"a" => [[0,0],[3,4]], "b" => [[1,1],[0,0],[9,8]], "c" => [[7,6]]}


# This is ugly but maybe you can get some ideas
arr.each do |c|
p "FROM a" if myhash["a"].include?(c)
p "NOT FROM a" unless myhash["a"].include?(c)
end

Harry

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