Ruby Hash: ordering a hash based on the values (which are arrays of values)

Question

I'm looking to return a new hash based on the reordering of values in the hash. The values, themselves, are arrays of ints.

For example:

hsh = {"c2" => [44,2], "c1" => [11,33], "c9" => [23,7]}

I would like to be able to return a reordered hash based on either value 0 or value 1 in the values.

Any help here is much appreciated - thanks all.

actually, rails has an ordered hash, and iirc, ruby 1.9 has an ordered hash too... — DGM
– DGM, Commented May 20, 2011 at 23:54
Ruby 1.9 remembers the insertion order of the hash, but it doesn't order it. — the Tin Man
– the Tin Man, Commented May 21, 2011 at 4:20

sawa · Accepted Answer · 2011-05-20 23:55:07Z

5

From the nature of the question, I assume this is for ruby 1.9.

p Hash[hsh.sort_by{|k, v| v[0]}]
# => {"c1"=>[11, 33], "c9"=>[23, 7], "c2"=>[44, 2]}

p Hash[hsh.sort_by{|k, v| v[1]}]
# => {"c2"=>[44, 2], "c9"=>[23, 7], "c1"=>[11, 33]}

answered May 20, 2011 at 23:55

sawa

169k51 gold badges287 silver badges398 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Gavin Over a year ago

Just what I was looking for @sawa - thank you. And yes, this is ruby-1.9.2

Jeremy Smith Over a year ago

How do you apply sort_by to hash when it's not listed as a method of that class?

sawa Over a year ago

@Jeremy In my case, I do it as usual because I already know how to use it. In your case, you can either (i) ask that as an independent question on Stackoverflow, (ii) look for better documentation, (iii) try to find a documentation more seriously using ri, rdoc, or (iv) just try it with various examples until you can infer how it works.

Collectives™ on Stack Overflow

Ruby Hash: ordering a hash based on the values (which are arrays of values)

1 Answer 1

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related