[ruby] How to sort a Ruby Hash by number value?

I have a counter hash that I am trying to sort by count. The problem I am running into is that the default Hash.sort function sorts numbers like strings rather than by number size.

i.e. Given Hash:

metrics = {"sitea.com" => 745, "siteb.com" => 9, "sitec.com" => 10 }

Running this code:

metrics.sort {|a1,a2| a2[1]<=>a1[1]}

will return a sorted array:

[ 'siteb.com', 9, 'sitea.com', 745, 'sitec.com', 10]

Even though 745 is a larger number than 9, 9 will appear first in the list. When trying to show who has the top count, this is making my life difficult. :)

Any ideas on how to sort a hash (or an array even) by number value size?

I appreciate any help.

Since value is the last entry, you can do:

metrics.sort_by(&:last)

That's not the behavior I'm seeing:

irb(main):001:0> metrics = {"sitea.com" => 745, "siteb.com" => 9, "sitec.com" =>
 10 }
=> {"siteb.com"=>9, "sitec.com"=>10, "sitea.com"=>745}
irb(main):002:0> metrics.sort {|a1,a2| a2[1]<=>a1[1]}
=> [["sitea.com", 745], ["sitec.com", 10], ["siteb.com", 9]]

Is it possible that somewhere along the line your numbers are being converted to strings? Is there more code you're not posting?

Already answered but still. Change your code to:

metrics.sort {|a1,a2| a2[1].to_i <=> a1[1].to_i }

Converted to strings along the way or not, this will do the job.