How to sort a hash by value in descending order and output a hash in ruby?

Question

output.sort_by {|k, v| v}.reverse

and for keys

h = {"a"=>1, "c"=>3, "b"=>2, "d"=>4}
=> {"a"=>1, "c"=>3, "b"=>2, "d"=>4}

Hash[h.sort]

Right now I have these two. But I'm trying to sort hash in descending order by value so that it will return

=> {"d"=>4, "c"=>3, "b"=>2, "a"=>1 }

Thanks in advance.

Edit: let me post the whole code.

def count_words(str)
  output = Hash.new(0)
  sentence = str.gsub(/,/, "").gsub(/'/,"").gsub(/-/, "").downcase
  words = sentence.split()
  words.each do |item|
    output[item] += 1 
  end
  puts Hash[output.sort_by{ |_, v| -v }]
  return Hash[output.sort_by{|k, v| v}.reverse]
end

Solution 1

Try:

Hash[h.sort.reverse]

This should return what you want.

Edit:

To do it by value:

Hash[h.sort_by{|k, v| v}.reverse]

Solution 2

Try this:

Hash[h.sort_by{ |_, v| -v }]

Comments

[Patrick Oscity]

Remember that hashes do not have an order previous to Ruby 1.9

[tipsywacky]

but that sort the key thought, i'm trying to sort the value

[tipsywacky]

hmmm....i thought that's the way too. How come I see unless1sunday1or1on2of2due1the5is1day2saturday1rent1falls1fi‌​rst2month2a1.. All the keys and values stuck together in the irb.

[Luke]

It comes out perfectly fine for me. Are you using something other than this test hash?

[tipsywacky]

nope... well, if that's the way to sort it. then it probably something else making it output the wrong hash. I'll double check. Thanks anyway.

[PJP]

"How come I see unless1sunday1or1on2of2due1the5is1day2saturday1rent1falls1fi‌​rst2month2a1", what version of Ruby are you using?